The 7th term of an arithmetic progression (AP) is 22 and the 12th term is 37. Which one of the following pairs of simultaneous equations correctly relates the first term a and the common difference d?
a) a+7d=22,a+12d=37
b) a+6d=37,a+11d=22
c) a+6d=22,a+11d=37
d) a+6d=22,a+12d=37