Provide the Proper Response $f(x)$ ?
A) $f(x)$ Must Be Continuous on Some Interval

Provide the proper response.
-When we define the definite integral, what is a necessary condition for the function $f(x)$ ?

A) $f(x)$ must be continuous on some interval $[a, b]$ .
B) We must be able to draw the graph of $f(x)$ .
C) $f(x)$ must be continuous everywhere.
D) $f(x)$ must be positive on some interval $[a, b]$ .