Answer: Option A
Explanation:
To get from A to A', what is done?
A is at the point (2,6) and A' is at the point (2,-1)
The x value of the two points stayed constant (didn't change) meaning that options C and D are invalid (because those two are transformations to the x-value)
Now let us take a look at options A and B which both concern the y value
The y-value of A is 6 and A' is -1
To get from 6 to -1, do you
a) subtract 7
or b) = multiply by -1
Let us test it out:
a) 6 - 7 = -1 (yes, it equals -1)
b) 6 * -1 = -6 (no, it does not equal the intended value of -1)
Thus correct choice is A, we subtract 7