Atrophy means waste away, especially as a result of the degeneration of cells, or become vestigial during evolution.
Option B is the correct answer because “to deteriorate” means to get degenerates with time, hence it is the correct answer.
Option A is incorrect because “to thrive” means to survive hence it would be the antonym of the given word.
Option C is incorrect because to succeed means to successfully complete a task, which is not relevant to the word given.
Option D is incorrect because “degenerate “ means to breakdown and get destroyed , which is a part of deterioration and atrophy hence incorrect.