If g′(3)=−4, which of the following statements is correct about the graph of y=g(x) at x=3?
a) The tangent at x=3 rises 4 units for every unit increase in x.
b) The tangent at x=3 falls 4 units for every unit increase in x.
c) The normal at x=3 has slope −4.
d) The tangent at x=3 falls 1 unit for every 4-unit increase in x."