Antonym of BOOST

Answer: Option A

Boost : help or encourage (something) to increase or improve.
Hinder : make it difficult for (someone) to do something or for (something) to happen.
Obstruct : block (an opening, path, road, etc.); be or get in the way of.
Discourage : cause (someone) to lose confidence or enthusiasm.
Rebuke : express sharp disapproval or criticism of (someone) because of their behaviour or actions.

Antonym of Boost is Hinder