Question

http://imgur.com/Zb27DdA
A mass slides on a frictionless ramp, moving through locations 1, 2 and 3 shown below. At which location(s) is the net acceleration of the mass aligned with the +y direction?

The answer is only at location 2, why?

I thought the net acceleration for one would be down the ramp, 2 would be up the ramp, and 3 to be directly down.