Question Detail
Question
The longest time period: a. Mesozoic b. Paleozoic c. Cenozoic d. Precambrian
Correct Answer
Option D is the correct answer.
Detailed Explanation
The Precambrian is a supereon that covers Earth's history from its formation about 4.6 billion years ago until the beginning of the Cambrian Period (~541 mya). It represents about 88% of geologic time, making it by far the longest. The others are eras within the Phanerozoic.
Hint
This vast stretch of time covers the first ~4 billion years of Earth's history.