Read the following passage to answer the question. The sentences are numbered to help you answer the questions.
(1) The solar system is made up of the sun and the planets that go around it. (2) The planet closest to
the sun is called Mercury (3) The planet next closest to the sun is Venus. (4) Earth is the third planet
and Mars is the fourth. (5) Life on Earth is thought to have begun about three billion years ago. (6) For
many millions of years, the most common life form was bacteria. (7) Scientists have tried hard to
understand how plants and animals developed from these simple, one-celled creatures.
1. The topic sentence in the first paragraph is number
O A.1
OB.5.
O C.4
O D.2