15. suppose a bill has passed both the house and the senate. it goes to the president at the beginning of the annual session of congress. the president doesn't sign the bill but holds it for more than 10 days. what happens to the bill? a. it cannot become law, but it has not been vetoed. b. it becomes law only if two-thirds of the house and senate vote for it. c. it has been vetoed. d. it becomes law.