Answer:
Answer C is correct.
Explanation:
f(x) clearly has a maximum: y = +10 at x = 0.
Analyzing g(x) = -(x + 1)^2 - 10, we see that the vertex is at (-1, -10), and that the graph opens down. Thus, -10 is the maximum value; it occurs at x = -1.
Answer A is false. Both functions have max values.
Answer B is false. One max is y = 10 and the other is y = -10.
Answer C is correct. The max value of f(x), which is 10, is greater than the max value of g(x), which is -10.
Answer D is false. See Answer B, above.