Which shows the expression below simplified?
(3.6 × 10^15) + (1.8 × 10^12)
a. 3.60018 × 10^15
b. 3.902 × 10^14
c. 3.618 × 10^15
d. 3.6018 × 10^15
(3.6 × 10^15) + (1.8 × 10^12)
a. 3.60018 × 10^15
b. 3.902 × 10^14
c. 3.618 × 10^15
d. 3.6018 × 10^15