I'm little confused with this excersise.....

if the derivative of y=k(x) equals 2 when x =1 , what is the derivative of

a k(2x) when x = 1/2?

b k(x+1) when x=0

c k((1/4)x) when x=4

in this excersise , the chain rule should be applied, but I don't know how. Can I get some help?