The value of $$\left(1\frac{1}{8} \div \frac{3}{4}\right)\div \left[\left(\frac{1}{2} of 1\frac{1}{2}\right) \div \left(3\frac{1}{2} - 1\frac{1}{4}\right) of \frac{3}{4} - \frac{3}{4} \div 2\frac{1}{4}\right] of \frac{3}{4}$$ is:

A

9

B

18

C

12

D

6