The evil moneylender

Your father has taken a loan from an ugly and old moneylender, who invites you and your father to his farm. He proposes that he would forgo the debt if you marry him. You and your father are horrified by the suggestion.

He informs that he would put a black and a white pebble into an empty money bag. The girl will choose, if she picks the black pebble, she would become his wife and debt would be forgiven. If she picks the white, she need not marry him and debt would still be forgiven. But if she refuses to pick a pebble, her father would be sent to the jail. The law permits immediate jail term in case of loan default.

While walking on the pebble strewn path, he picks up two pebbles. You notice that he picked up two black pebbles and he put them into the bag.

Now he invites you to pick a pebble from the bag.

What will you do?