Why must you call session_start() prior to any output?
Because session_start() sets some HTTP headers.
Correct:
Because session_start() sets some HTTP headers.
Answer C is correct.Answer A is incorrect because this is a technical necessity, not a best practice. Answer B is incorrect because accessing the session data store is completely independent of whether there has been any output.Answer D is incorrect because you can set other HTTP headers after a call to session_start().