Ice-choked tower, Mondavia, Nanglangka.
The card speaks of discarding a card. Is this a random card from the hand or does the doctor get to choose?
The Master player chooses and discards a card from his hand. If it's a random discard, the card will say.
The default position for cards such as these is always 'from hand' - and unless specified otherwise, the opponent chooses what to lose.