Answer:
It would be C, 64.387
Explanation:
First, you have to solve 7x1/1000. This equal to 7/1000 which should be converted into decimal form (since all the answers are in decimal form). 7/1000 is 0.007 in decimal form.
It is 0.007 since in 7/1000, the denominator is 1000, making 7 in the thousandths place (the 3rd digit to the right of the decimal point).
The only number that contains 0.007 is the 3rd one, making it your answer.