Which sentence is an example of direct characterization?

Jake and Sam shouldered the next pair of fifty-pound food packs and began another long trudge up the hill.

"Oh, this is just swell," Jake said, covering his ears to block out the sound.

Jake had a short fuse when he was under stress, and this entire adventure was not bringing out the best side of his personality.

Of course, staking a claim and striking it enormously rich on Klondike gold had seemed like a wonderful idea last summer.