A portion of the graph of f(x) = −x2 − 10x − 21 is shown. Which of the following describes all solutions for f(x)? a partial parabola opening down and passing through negative 7 comma 0 and negative 3 comma zero with endpoints at negative 8 comma negative 5 and negative 2 comma negative 5 (x, −x2 − 10x − 21), where −7 ≤ x ≤ −3 (x, y), where −7 ≤ x ≤ −3 (x, −x2 − 10x − 21), where −8 ≤ x ≤ −2 (x, y) for all real numbers