Which of the following correctly describes the result of the expression ∫f(x)dx?
a) The exact numerical area under y=f(x) from x=a to x=b.
b) A family of antiderivatives of f(x) plus an arbitrary constant C.
c) A single antiderivative of f(x) (no constant term).
d) The limit of the sum ∑f(xi)Δx as Δx→0 over [a,b].