The correct answer is: C. (6 x 1/10) + (2 x 1/100) + (4 x 1/1000).
This is because this is equal to adding .600 + .02 + .002.
Each number within the parentheses is being multiplied with the place they are in. Tenths, hundredths, and thousandths, hence the fraction to place them there.
I hope this helps!
