Final answer:
The vast amount of time that precedes the Paleozoic Era is called the Precambrian.
Step-by-step explanation:
The correct answer is d) Precambrian. The Precambrian refers to the vast amount of time that precedes the Paleozoic Era. It is the earliest part of the Phanerozoic Eon and is divided into three eons: Hadean, Archean, and Proterozoic. The Precambrian includes the formation of Earth and the development of life before the Cambrian explosion.