$1)$ Answer the following question correctly and detailedly showing all steps.

A$.$ Simplify the expression F$($A$.$B$.$C$.$D$)=(0,2,4,5,6,8,10)$ using K$-$maps

B$.$ Design a one $(01)$ bit full subtractor

C$.$ Minimize the following function F$($ABCD$)=$m $(6,7,8,9)$ assuming that the condition AB $=11,$ can never occur. Draw the schematic using NAND gates

D$.$ Design a BCD counter Using JK flip$-$flops $($hints: a counter that counts from $0-9$ and repeats$)$