Multiply ( 4.7 x 10 ^4) by ( 6.4 x 10 ^15). Express your number in scientific notation.
A3.008 x 10 ^20
B3.008 x 10 ^60
C3.008 x 10 ^61
D30.08 x 10 ^19
A3.008 x 10 ^20
B3.008 x 10 ^60
C3.008 x 10 ^61
D30.08 x 10 ^19