A continuous function f satisfies f′(x)>0 for x<2, f′(2)=0, and f′(x)>0 for x>2. What can you conclude about x=2?
a) x=2 is a point of local minimum
b) x=2 is neither a maximum nor a minimum
c) x=2 is the global minimum
d) x=2 is a stationary point of inflection