The correct option is C not to go out
The given sentence is in the indirect mode of narration, where the direction of not going out has been transformed into the indirect form, not directly addressing the subject. Option C is the most appropriate answer because it consists of the necessary format in the correct syntax. Option B lacks the preposition to hold together the verb and the adverb. Options A and D contain variations of the auxiliary verb do, which directly address the subject, thus not fitting the syntax of indirect speech. Hence, Options A,B and D are all incorrect.