Answer:
4. Hypothesize.
Step-by-step explanation:
Some scientists hypothesize that by sensing a change in barometric pressure or electricity, certain species of fish may be able to portend seismic events; just before a recent earthquake, several fish were observed leaping into the air from the ocean.
The answer cannot be repudiate for it means that the facts or information/ claim is rejected. Authorize, foresee, question and contend are also wrong as they do not support the claim that follows in the next words.