A formal language is recursive if : A. a total turing machine

a-formal-language-is-recursive-if-a-a-total-turing-machine

A formal language is recursive if :

A. a total turing machine exists

B. a turing machine that halts for every input

C. turing machine rejects if the input does not belong to the language

D. all of the mentioned

The question was asked during an interview for a job.

The origin of the question is The Universal Language-Undecidability in chapter Undecidability of Automata Theory

Correct option is D. all of the mentioned

To explain I would say: A formal language is called recursive if it is a recursive subset of the set of all possible  finite sequences over the alphabet of the language.