Question

more than 20 species of sharks and rays dwell in gabons new 18,000 - square - mile marine sanctuary, which offer a refuge to many rare and threatened species. choose 1 answer: a no change b have offered c were offering d offers

Explanation:

The subject "marine sanctuary" is singular. The present - tense verb should agree with it. "Offer" in the original is plural - form and incorrect. "Offers" is the correct singular - present form.

Answer:

D. offers