If GCD(a,b)=12\text{GCD}(a, b) = 12GCD(a,b)=12 and LCM(a,b)=720\text{LCM}(a, b) = 720LCM(a,b)=720, how many possible pairs (a,b)(a, b)(a,b) exist?
222
444
888
161616