$2-8.$ Using DeMorgan's theorem, express the function

$F=\frac{A}{b}ar(B)C\frac{+}{b}ar\frac{A}{b}ar(C)+AB$

$($a$)$ with onlyOR and complement operations.

$($b$)$ with only AND and complement operations.

$($c$)$ with only NAND and complement operations.