It's an easy A)
How? You ask.
Well, we're given that the selling Price of any article is a whole number + $.99 which means the value is $X.99. We just need to find a whole number that can give us a value of X.
Whole number means the money or number can be any Positive number. As its money we can't take a negative number.

Statement 1) does exactly that. By giving us total price $36.72
One can determine
That she bought 37 items,
As 38*0.99 = 36.72

And remember 0 is a whole number.
But we don't need to do all this math.
Sufficient

Statement 2)
Isn't really of much use here. We can't calculate the number of items just by this information. We require either the number of items or the total amount which she paid.
Hence, insufficient
Answer A