In a geometric sequence ana_nan, if a1+a2=4a_1 + a_2 = 4a1+a2=4 and a3+a4=36a_3 + a_4 = 36a3+a4=36, what is the common ratio rrr?
r=2r = 2r=2
r=3r = 3r=3
r=−3r = -3r=−3
r=−2r = -2r=−2