Calculate the L.C.M of 4/9, 5/ 7, 9/13, 7/15 is :	Choose the correct choice from the following answers:
A) 1230
B) 1290
C) 1260
D) 1240
E) 2260

Rationale: "required l . c . m = l . c . m . of 4 , 5 , 9 , 7 / h . c . f . of 9 , 7 , 13 , 15 = 1260 / 1 = 1260 answer is c"
Answer: C