For the function f(x) = –(x + 1)^2 + 4, identify the vertex, domain, and range.
a. the vertex is (–1, 4), the domain is all real numbers, and the range is y ≥ 4.
b. the vertex is (–1, 4), the domain is all real numbers, and the range is y ≤ 4.
c. the vertex is (1, 4), the domain is all real numbers, and the range is y ≥ 4.
d. the vertex is (1, 4), the domain is all real numbers, and the range is y ≤ 4.