Using the intermediate value theorem, determine, if possible, whether the function f has at least one real zero between a and b. f(x) = 5x - 2x - 4; a = -5, b=-1 Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice. OA. By the intermediate value theorem, the function has at least one real zero between a and b because f(a) = and f(b)= O B. By the intermediate value theorem, the function does not have at least one real zero between a and b because f(a)= OC. It is impossible to use the intermediate value theorem in this case. (Simplify your answers.) and f(b)= (Simplify your answers.)