What's the answer to this multiple choice?

https://halo.gcu.edu/quiz/96fa0ed5-046b-49a9-8201-7115fe370482/start-quiz/2df01513-76f alo learn MESSAGES Quiz Progress sessment Title Topic 2 Assessment 15/20 Answered U U. Clean the computer's memory. 2 V 3 V Question 16 4 What is considered the "brain" of the computer? 5 6 Select one 7 A. RAM O B. GPU O O C. CPU 10 O D. Hard drive 11 12 17 Type here to search BGCO W ASU