Shaniqua starts a bank account with a $120 deposit. By the end of 12 months, she hopes to have saved $900. She knows that she can save $30 per month from her paycheck, but can earn some extra money by tutoring on the weekend. How much extra per month does Shaniqua need to save in order to meet her goal? Select the equation that best represents this situation and solution.
A.120 + 12(30 + x) = 900; $35
B.120 + 12(30 + x) = 900; $420
C.120 + 12(30) + x = 900; $35
D.120 + 12(30) + x = 900; $420