投資

この新しいシステムの導入には、多額の資金が ___ されるだろう。

The correct answer is 「投資」(とうし), meaning "investment." The sentence describes the introduction of a new system that requires a large amount of funds, indicating that money will be put into it with the expectation of future returns or benefits. This directly aligns with the concept of investment. 「放棄」(ほうき) means "abandonment" or "giving up"; funds are not abandoned in this context. 「撤退」(てったい) means "withdrawal" or "retreat"; funds are not withdrawn but rather allocated. 「享受」(きょうじゅ) means "enjoyment" or "reception of benefits"; while a system might eventually bring benefits, the initial act is the provision of funds, not the enjoyment of them.

正解は「投資（とうし）」です。新しいシステムを導入する際に多額の資金を投入し、将来的な利益や効果を期待する行為を指します。「放棄」は捨てること、「撤退」は引き下がる・引き揚げること、「享受」は利益や恵みを受けることを意味し、文脈に合いません。