Whoever opinion polls show has the highest chance of winning an immediate election.
The Tories have only one important task ahead of them - making sure Jeremy Corbyn doesn't take power. There'll be other challenges, but none of them will matter if that's not accomplished first.
I think it's Hunt. Javid is the most qualified choice, but he would rile up the nativist populists and send UKIP voters over to Labour in droves.
Isn't Hunt massively unpopular after six years as Health Secretary and a not impressive stint as Foreign Secretary? I'd be truly surprised if he didn't have a sky high rate of disapproval.