Passive Sentence: The proposal was approved by the committee after thorough deliberation.

Active Sentence: The committee approved the proposal after thorough deliberation.

Explanation of Changes:

1. The subject of the sentence (“the committee”) was placed at the beginning to make it the actor performing the action.
2. The verb (“approved”) was modified to fit the active voice structure.
3. The sentence retains its original meaning while improving clarity and readability.