Which statement describes the domain and range of the exponential function f(x) = – 4x?

A.The domain and range are both the set of all real numbers.
B.The domain is the set of all real numbers and the range is the set of all negative real numbers.
C.The domain is the set of all real numbers and the range is the set of all real numbers less than or equal to –4.
D.The domain is the set of all real numbers greater than 0 and the range is the set of all real numbers less than 0.