General equation of line is \(y=mx+n\) where m is slope and n is point on y-axis. So just use points in question to determine what m and n must be. Let me show you.
For A(0,1), put this point in \(y=mx+n\) then you have \(1=m.0+n\) Hence \(n=1\)
Now use second one that is B(1,5), then you get \(5=m.1+1\) since \(n=1\). Finally you get \(m=4\) that is slope.
So you are right. It is D
