Which of these is correct?

Question

A: (2.9 X 10^8) (1.3 X 10^7) = 3.77 X 10^15
B: (9.9 X 10^7) (5.8 X 10^6) = 5.72 X 10^13
C: (8.8 X 10^8) (4.2 X 10^7) = 13 X 10^15
D: (4.6 X 10^5) (2.1 X 10^4) = 2.5 X 10

Answer 1

B: (9.9 X 10^7) (5.8 X 10^6) = 5.72 X 10^13