16 A good way to ....... a problem is to think about it calmly and carefully.

Rationale:

• The sentence describes a positive outcome of dealing with a problem.
• 'Gain' means to obtain or acquire something, often through effort.
• 'Win' and 'beat' usually refer to competitions or overcoming an opponent, not necessarily solving a problem in this context. 'Gain' implies a positive result from the action.

Answer: C gain