💡 Detailed Explanation
The correct choice is Option 3: 'Rain.' The weather forecast states: '午前中は曇りですが、昼過ぎから雨が降り始めるでしょう' (It will be cloudy in the morning, but it will start raining from early afternoon). Since early afternoon ('昼過ぎ') onwards belongs to the afternoon, the weather in the afternoon ('午後') is rain.