Estimate the value as a product of a single digit and a power of 10. the one with () are exponets .... 906,000,000,000 A.9×10 (10) B.9×10 (11) C.9.06×10 (11) D. 9.06×10 (12)

The answer would be A. If it wasn't limited to a one digit number multiplied by a power of 10 then the answer would be 9.06*10^10, but the limitation requires a single digit leaving only the answer 9*10^10 because 10^10= 100,000,000,000. That multiplied by 9 would give you 900,000,000,000.