Find the product of (3.7 × 10^4) and 2.

A. 7.4 × 10^4
B. 0.74 × 10^4
C. 74 × 10^4
D. 7.4 × 10^3


I believe it is A though I'm not good with the ending (10^4 x 10^0, I believe), I think it is 4, but it could be 3. Help, please?