The correct answer is (D) To decline; to worsen, diminish, waste or fade away, recede, or decay. Also, to flow backward or away; as the water of a tide; to draw back from the shore (of tidal water).

Ebb comes from Old English ebba, ebbian (low tide), Old Saxon ebbia, German ebbe.

Examples of use:

• His confidence ebbed as the day of the match approached.
• Life slowly ebbed from stricken animal.