The second choice is not a relation.
The first and third choices have multiple (input, output) pairs that have the same input. Such a relation is not a function. Any time you see this, you know the relation is NOT a function.
The best answer is the 4th choice ...
... {(0, -9), (-9, 0), (-3, -3)}
The change in x, as we move from left to right, is 7-4, or +3.
The corresponding change in y is -2i-2i = -4i.
Use the Pythagorean Theorem to find the length of this line segment:
d = distance from 4+2i to 7-2i= sqrt( [3]^2 + sqrt( [-4]^2 ) = sqrt(9+16) = 25 (ans.)
The function given to us is : 
We want to see which function represents the horizontal compression of f(x) by a factor of 4
We can compress a function horizontally by multiplying the x by a constant number, in this case multiplying x by 4
So horizontal compression of 
This matches with the option B = 
Hence, your answer (B) is correct.
She removed 12 marbles because 3×12=36 and you can do commutative property and do 12×3= what? 36!
3 & 5 are the coefficient ones because they are multiplying a variable
