If You Compared the Diameter of the Earth (13,000 Km)to

Multiple Choice

If you compared the diameter of the Earth (13,000 km) to 1 second,what unit of time would be equivalent to the size of our Galaxy,whose diameter is 1.5 × 10²¹ m __________,which is the length of time between now and when __________.

A) 3 million years; man's ancestors first began to walk upright
B) 30,000 years; humans first arrived in the Americas
C) 400 years; Galileo used a telescope to demonstrate that Jupiter had moons that revolved around it
D) 4 billion years; the Solar System was born