Question

this planet is similar in size to the earth, has a thick atmosphere of carbon dioxide, and is considered earth’s sister planet. a mars b venus c saturn d mercury

Explanation:

Venus is similar in size to Earth, has a thick atmosphere mainly composed of carbon - dioxide, and is often called Earth's sister planet. Mars has a thin atmosphere, Saturn is a gas giant much larger than Earth, and Mercury is much smaller than Earth.

Answer:

B. Venus