A worker in a factory earns $10 an hour. The worker works 10 hours a day for 10 days straight before a vacation. How much money did the worker earn before going on vacation?

a.10^2

b. 10^1

c. 3^10

d. 10^3

Expressions Unit test, 6th grade.
if you guys know the rest of the answers it would be extremely helpful!

d. 10^3