Correct Answer: Valley

Solution : The correct choice is the second option.

The term mound refers to an elevated area or heap, typically created by the accumulation of soil or earth. In contrast, a valley denotes a low-lying tract of land between hills or mountains. The opposition between an elevated mound and a depressed valley makes the second option the most appropriate choice as the antonym.

The meanings of the other options are as follows:

• Victory: This term signifies success or triumph.
• Bell: This term refers to a musical instrument.
• Prominence: This term means the state of being important or famous.