Quoting OGDirty LurkerTBTM:" eeeeeeeeeeeep ok. i've been giving my toddler choices lately. this morning I said 'do you want underwear ... [snip!] ... accidents. i'm about to give up yet again. Am I doing something wrong? I take him and ask him if he has to go every 10-15 min."
Sounds like he's not emotionally ready but is physically ready.
Offering choices is good, but I would suggest making it a choice of "which undies" not "undies or diaper" kwim? And what helped our LO is having him help throw away all diaps in a trash bag to get the kinesthetic and visual cues of "oh smurf...this IS it"
Going naked also helped a lot more than with just undies...I can only assume when they feel something on them they equate that to pee in it since that's what they've done literally their whole lives.
And our LO took until 3 when he was behaviorally/emotionally all onboard.