Answer :
The answer is C because you divide the P so you get KP=AR then you finish the rest
K=ar/p isolate R
K/a=R/p divide a to both sides
Kp/a=r multiply p to both sides
Kp/a=r is your answer
K/a=R/p divide a to both sides
Kp/a=r multiply p to both sides
Kp/a=r is your answer