[Closed] NL2 KK fold on flop after all in?

I]Hand converted with online PokerStrategy.com hand converter:

Play hand

$0.01/$0.02 No-Limit Hold'em (9 handed)

Known players:
[tg]UTG2$1.62:///////;MP1 (Hero)$2.26:///////;MP2$1.99:///////;MP3$5.00:///////;CO$1.40:///////;BU$3.13:///////;SB$2.04:///////;BB$2.66:///////;UTG1$3.22:///////;[/tg]

Preflop: Hero is MP1 with K:d, K:c.
2 folds, Hero raises to $0.08, 2 folds, CO calls $0.08, BU calls $0.08, SB folds, BB calls $0.06.

Flop: ($0.33) 5:h, 6:s, 8:s (4 players)
BB checks, Hero bets $0.32, CO folds, BU calls $0.32, BB raises to $2.58(All-In), Hero folds, BU folds, BB gets uncalled bet back.

Final Pot: $0.97.

I decided to fold because his play suggested he had hit a set or stronger. What else hand could he play like this?

Thank you in advance!