Add the following numbers, using scientific notation and the correct amount of significant digits. 3.4⋅10 8m + 4.56⋅10 9m = _____.
A 4.9 ⋅10 9m
B 4.9 ⋅10 8m
C 7.96 ⋅10 9m
D 7.96 ⋅10 8m