The series follows a similar pattern that is,
12 × 1.5 = 18
18 × 1.5 = 27
27 × 1.5 = 40.5
40.5 × 1.5 = 60.75
60.75 × 1.5 = 91.125
91.125 × 1.5 = 136.6875
The Error Term is 26.5
The Term which will Replace it will be 27
The correct option is (A): 26.5