The Universality Principle Means That

The Universality Principle means that

A) any problem that can be correctly represented in binary can be solved by a computer
B) a program that runs on one computer can be run on any other, although it might take longer
C) if a computer is powerful enough to solve any NP-complete problem, it can solve any other problem
D) if a problem can be solved by one computer, it can be solved by any computer, although perhaps more slowly