the microbead-free waters act aims to eliminate tiny plastic beads from soaps and other beauty products…

Brief Explanations:

The original sentence has a run - on error. A semicolon (;) is used to separate two independent clauses. "The Microbead - Free Waters Act aims to eliminate tiny plastic beads from soaps and other beauty products" and "microbeads pollute the water and cause internal abrasions in fish" are both independent clauses. A comma (,) alone (as in option B) is not sufficient to separate them (comma - splice error). Option C has incorrect punctuation placement. Option D correctly uses a semicolon to separate the two independent clauses.

Answer:

D. products; microbeads