On a quiz, a student factored 25x² - 15x + 2 by grouping as follows.
25x² - 15x + 2 = 25x²5x - 10x + 2

= 5x(5x − 1)− 2(5x − 1) This is the student's answer.

He thought his answer was correct since it checked by multiplying. What went wrong? What is the correct factored form?

Select the correct choice below and fill in the answer box(es) to complete your choice.
A. The student did not factor the groups correctly. The correct factored form is □
B. The expression is the sum of two terms. He needs to factor out the common factor. The correct factored form is □
C. The pair of integers to write the middle term is not correct. The correct factored form is □
D. The sign between the two terms is not correct. The correct factored form is □​