We are given inequality : y-3x<-x+4.
We need to isolate it for y on left side.
In order to isolate it for y, we need to get rid -3x from left side.
3x is being subtracted from left side.
The reverse operation of subtraction is addition.
Adding 3x on both sides, we get
y-3x+3x<-x+3x+4.
y < 2x+4
Therefore, correct option is second option.
B. y < 2x + 4.