Pls Help The text describes a major problem affecting a significant number of dams throughout the United States. What is this problem?

A. Many dams are built with a thicker core of impermeable clay.

B. Many dams need to be upgraded but funding and inspection staffing is limited.

C. Many dams are strengthened by zones of compacted material.

D. Many dams are built in areas with lots of storms, and are likely to overflow.