GMAT Critical Reasoning (CR) | Re: To reduce the danger to life and property posed by major

To prevent damages caused by earthquakes, scientists will rely on catfish because they swim erratically before earthquakes.

Which of the following, iftrue, most seriously undermines the usefulness of the proposal?

We have to look for an answer that undermines the connection earthquake => movement of catfish.
E does just that:
(E) Even very slight, fleeting tremors cause catfish to swim erratically
The connection in undermined now

Initially I was quite sure of C, so I want to explain why