Add support for answering questions using letter keys.
Add support for answering questions using letter keys.

hlplab/hlpspr1,wenru/ibex,addrummond/ibex,hlplab/hlpspr1,hlplab/hlpspr1,wenru/ibex,wenru/ibex,addrummond/ibex,wenru/ibex,addrummond/ibex,addrummond/ibex