Answer:
D. 10^10
Explanation:
Multiplying numbers with exponents rule :
![a^b*a^c=a^b^+^c](https://img.qammunity.org/2023/formulas/mathematics/high-school/ge84ia0mtz0f06bafuu17ojvfktu0k8vj9.png)
explanation of rule : we simply keep the bases the same and add the exponents.
10^3 • 10^7
keep the base as 10 and add the exponents
![10^3 * 10^7 =10^3^+^7=10^1^0](https://img.qammunity.org/2023/formulas/mathematics/high-school/x6beaa95jx77uzc15p0vo9cbee3rtq45zy.png)
Keep in mind that this only works when the bases are the same.