Tyler’s math class found that it would take 2.5×10^8 dollar bills to cover a square mile area. The surface area of the United States is about 3.8×10^6 square miles. About how many dollar bills are needed to cover the United States?
A)6.3×10^14
B)9.5×10^14
C)6.3×10^48
D)9.5×10^48