​how do u do this

If it is parallel then it has to have the same gradient which is 4

So it has to be either 

H      y=4x+19

or

K      y=4x+21

Now it goes through (-5,1)

For H when x=-5     y= 4*-5 +19 = -20+19=-1 

For K when x=-5     y= 4*-5 +21 = -20+21= +1

So the answer is K