Unsolvable Problems Related to the Halting Problem Have the Following

Multiple Choice

Unsolvable problems related to the halting problem have the following practical consequence: ____.

A) a program can be written to decide whether any given program run on any given input will produce some specific output.
B) a program can be written to decide whether any two programs are equivalent.
C) a program can be written to decide whether any given program always stops eventually, no matter what the input.
D) no program can be written to decide whether any given program run on any given input will ever produce some specific output.