'Which of the following statements is true?
Every problem can be solved with an algorithm for all possible inputs, in a reasonable amount of time, using a modern computer:
Every problem can be solved with an algorithm for all possible inputs, but some will take more than 100 years, even with the fastest possible computer:
Every problem can be solved with an algorithm for all possible inputs, but some of these algorithms have not been discovered yet:
There exist problems that no algorithm will ever be able to solve for all possible inputs_'