It's first important to remember a few things: A reaction is spontaneous (in the forward direction) if K>1, delta G = - , and EMF = +.
Though I dont' remember encountering a problem like this in the past, I can deduct from the info I just wrote that since EMF = -, it cannot be spontaneous in the forward direction, so it must be spontaneous in the reverse. It's generally one or the other. Just manipulate the above info to come to ur answer.
because in this problem emf is negative, it makes G positive and a rxn can only proceed in the forward direction if G is negative. Also because G is nonsponatnous in the forward direction, this would make the reverse process spontaneous.