Both A) and C) are correct. Moving to the left is more negative (x) and moving up is more positive (y). Hence x translating -4 --> -6 is 2 units left [A], and y translating 2 --> 4 is 2 units up [C].
So the number of pencils bought can be represented by an equation: , where n is the number of notebooks bought. Since Helen bought 5 notebooks, simply plug 5 into n: . So Helen bought 12 pencils.
, where n is the number of notebooks bought. Since Helen bought 5 notebooks, simply plug 5 into n: 
. So Helen bought 12 pencils.