The correct option is
D 1/8
Given
sin12sin48sin54
Multiplying and Dividing by 2
12(2sin12sin48)sin54
(cos(A−B)−cos(A+B)=2sinAsinB)
12(cos36−cos60)sin54
12(cos36sin54)−12(12sin54)
Multiplying and Dividing by 2
14((2cos36sin54)−sin54)
(sin(A+B)−sin(A−B)=2cosAsinB)
14(sin90−sin(−18)−sin54)
14(1+√5−14−√5+14)
14(4+√5−1−√5−14)
14(24)
18