For a curve defined by x=f(t),y=g(t), suppose at t=1 we have g′(1)=0 and f′(1)=0. What can be concluded about the tangent at the corresponding point?
a) The tangent is horizontal.
b) No tangent exists at that point (the curve has a cusp).
c) The nature of the tangent cannot be determined from the given data.
d) The tangent is vertical.