Designing complex cmos circuits
The answer to your question is very straightforward: use an inverter to generate \$\overline{B}\$ from input \$B\$. 

Moreover, CMOS logic is inherently negative, therefore, I would advice using De Morgan to make your life easier and just insert an invert at the output node.

$$ \overline{F} = \overline{A+\overline{B}C}$$

The solution below uses 10 transistors.