The answer is B.) The safari stopped at an oasis, a moist fertile spot in the desert.
The appositive phrase is a moist fertile spot in the desert. You can read the rest of the sentence without that part and still have a complete sentence. It describers oasis.
The answer is B because he keeps mocking him and making rude remarks about him
Jane and jasmine liked going to the mall where THEY could buy new earrings