Please do not allow people to call SMS 2FA. For it to be 2FA, it must be: something I know alone, something I possess alone, something I am alone. Otherwise, it's just another account identifier (and likely spoof-able). SMS and phone numbers are none of these.
In same vein, I wish security questions would die in a fire. Always treat them like additional passwords: use nonsensical words and store them in your password manager.