Question

If for a function y=f(x), the conditions:
dy/dx>0 and d^2y/dx^2<0
can be verified over the whole domain, this means that:
a) y increases with x up to some point, and from this point y decreases with x
b) y decreases with x at a decreasing rate
c) y increases with x at an increasing rate
d) y increases with x at a decreasing rate