Shayna enlarged a square photo by adding 10 inches to each side so it could be seen on a large poster. The area of the enlarged photo is 256 square inches. In the equation (x + 10)2 = 256, x represents the side measure of the original square photo.

What were the dimensions of the original photo?

4 inches by 4 inches
6 inches by 6 inches
10 inches by 10 inches
12 inches by 12 inches