C. I think C, because it could be introduction to the plot
33 photos in a 4x to 7x ratio
4x + 7x = 33
11x = 33
x = 3
33 photos can be put in a 4(3) to 7(3) ratio
which is a 12 to 21 ratio
so 12 photos on one side, and 21 on the other side to get the ratio of 4 to 7
Note:
<span>a(b) = ab = a x b = a times b</span>
