The correct answer is 正当 (seitou). In the sentence 「会議で発言する前には、まず＿＿＿な手続きを踏む必要がある。」 (Before speaking at the meeting, you first need to go through the ___ procedures.), the word 正当 fits perfectly. **正当 (seitou)** means 'proper', 'legitimate', or 'justifiable'. It refers to something that is correct according to rules, logic, or morality. The phrase **正当な手続き (seitou na tetsuzuki)** is a common and natural collocation that means 'the proper/correct procedures'. The sentence is stating the need to follow the formally established, correct steps before speaking, making 正当 the ideal choice. Common Mistakes / Nuances: ❌ 有効 (yuukou): This choice is incorrect. **有効 (yuukou)** means 'valid' or 'effective'. It is used when something has a binding effect or can be used within a specific timeframe, like an **有効な切符 (yuukou na kippu - a valid ticket)** or a contract. It can also mean 'effective', as in an **有効な手段 (yuukou na shudan - an effective method)**. While a procedure could be effective, the sentence's context emphasizes following the *formally correct* steps, not whether those steps are effective or currently valid in a legal sense. Therefore, 有効 is not the best fit. ❌ 得意 (tokui): This choice is incorrect. **得意 (tokui)** means 'to be good at', 'one's strong suit', or 'one's specialty'. It is used to describe a person's skills or abilities. For example, **数学が得意です (suugaku ga tokui desu - I'm good at math)**. It makes no sense to describe a 'procedure' (手続き) as being 'good at something'. This word is used for people, not for processes or rules. ❌ 利口 (rikou): This choice is incorrect. **利口 (rikou)** means 'clever', 'smart', or 'wise'. It is typically used to describe the intelligence of people or animals, such as a **利口な犬 (rikou na inu - a smart dog)**. It cannot be used to describe an inanimate concept like a 'procedure' (手続き). A procedure can be well-designed or efficient, but not 'clever' in the way a person is. Using 利口 here would be unnatural.

正解は「正当（せいとう）」です。問題文「会議で発言する前には、まず＿＿＿な手続きを踏む必要がある。」において、「正当」が最も適切です。 **正当 (seitou)** は、「道理にかなっていて正しいこと、法規にかなっていること」を意味します。ルールや論理、道徳に照らして正しい状態を指します。**「正当な手続き（せいとうなてつづき）」** は「決められた正しい手順」という意味で、非常によく使われる自然な組み合わせです。この文は、発言する前に定められた正しい手順に従う必要性を述べているため、「正当」が完璧に当てはまります。 Common Mistakes / Nuances: ❌ 有効 (yuukou): This choice is incorrect. **有効 (yuukou)** means 'valid' or 'effective'. It is used when something has a binding effect or can be used within a specific timeframe, like an **有効な切符 (yuukou na kippu - a valid ticket)** or a contract. It can also mean 'effective', as in an **有効な手段 (yuukou na shudan - an effective method)**. While a procedure could be effective, the sentence's context emphasizes following the *formally correct* steps, not whether those steps are effective or currently valid in a legal sense. Therefore, 有効 is not the best fit. ❌ 得意 (tokui): This choice is incorrect. **得意 (tokui)** means 'to be good at', 'one's strong suit', or 'one's specialty'. It is used to describe a person's skills or abilities. For example, **数学が得意です (suugaku ga tokui desu - I'm good at math)**. It makes no sense to describe a 'procedure' (手続き) as being 'good at something'. This word is used for people, not for processes or rules. ❌ 利口 (rikou): This choice is incorrect. **利口 (rikou)** means 'clever', 'smart', or 'wise'. It is typically used to describe the intelligence of people or animals, such as a **利口な犬 (rikou na inu - a smart dog)**. It cannot be used to describe an inanimate concept like a 'procedure' (手続き). A procedure can be well-designed or efficient, but not 'clever' in the way a person is. Using 利口 here would be unnatural.