$1.$ The statement $$ P$1$DIR $|=0$x$01$; $$ will change P$2$IN by :

a$)$ setting bit$0$ high and not effecting the other $7$ bits

b$)$ clearing bit$0$ low and not effect the other $7$ bits

c$)$ setting bit$0$ high and clearing the other $7$ bits to low.

b$)$ clearing bit$0$ low and setting the other $7$ bits high.$$