Which expression is equivalent to 100k^2 - 25k?

A.) 25(4k - 1)

B.) 25(4k + 1)

C.) 25k(4k - 1)

D.) 25k(4k + 1)

The expression 100k^2 - 25k can be factored out common factors of 25k. The correct answer is C.) 25k(4k - 1).