Explanation:

Correct option is 4: Enthusiastic

Proactive implies taking initiative by acting in advance rather than responding to a situation after it happens. It's about anticipating and preventing potential problems or tasks.

Heedless means showing a reckless lack of care or attention. This is the opposite of proactive, as it suggests not thinking ahead.

Short-sighted refers to a lack of foresight or planning for the future. It implies focusing only on immediate issues, contrary to being proactive.

Reactive is responding to events or situations as they happen, rather than planning and acting ahead. This is the opposite of proactive.

Enthusiastic means showing intense and eager enjoyment, interest, or approval. While it involves energy and eagerness, it does not specifically relate to anticipation or planning.

The most appropriate synonym for proactive is none of the options. But if we are to choose one from the given options then option 4. Enthusiastic is a close choice.