I thinks it's D, due to the process elimination
Ben's estimate gives 7 g of nickel; the actual amount is 8.03 g.
In 1 g of the substance, there is 0.52 g of copper and 0.25 g of zinc; this gives
0.52+0.25 = 0.77 g of the substance.
The remaining part of the substance is nickel:
1-0.77 = 0.23 g of nickel.
Using Ben's estimate, 0.2 g of nickel per gram of substance, we have
0.2(35) = 7 g of nickel in 35 g of the substance.
The actual amount is 0.23(35) = 8.03 g of nickel in 35 g of the substance.
This is not an integer; an integer is a whole number that can be positive, negative, or zero such as -1, 0, and 1.
