This is a function problem involving nested functions. An easy way of thinking of functions is as though they're a find and replace in a word processing document. For example, if f(x) = x^2 + 2x + 1, then when they give you f(2), you can simply replace every x you see with a 2, giving you 2^2 + 2x2 + 1 = 9.
In quantity A and B they've given us nested functions, one inside the other. In cases like these, simply do the inside one first, then the outside one next. Since quantity A is f(g(–1)), let's do g(1) first. Since g(x) = x  2, we can substitute x for 1, giving us 1  2 = 3. Now we plug 3 into the outside function, which is f(x) = x^2 + 1, giving us (3)^2 + 1 = 10.
Let's do the same for quantity B, in which the inside function is f(x). So we'll plug 1 into f(x) first, and then the result into g(x) next. Plugging 1 into x^2 + 1 gives us (1)^2 + 1 = 2, and plugging 2 into x  2 gives us 2  2 = 0.
Since quantity A gives us 10 and quantity B gives us 0, the answer is A.
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