Joe wrote this expression to describe the number of tickets he gave to his friends. 10−t   Which situation could be described by this expression?

A Joe knows he started with 10 tickets. He does not know how many tickets he gave away.

B Joe knows he has 10 tickets left. He does not know how many tickets he gave away.

C Joe knows he gave away 10 tickets. He does not know how many tickets he has.

D Joe knows he has 10 tickets left. He knows he gave away half of his tickets.