Which setting determines whether users can log in and create sessions?

Correct answer: Login Hours

Option A is correct because Salesforce Login Hours settings on a profile or permission set define the specific days and times during which users assigned to that profile are permitted to start new login sessions, directly controlling whether a session can be created. Option B is wrong because Password Policy governs password complexity, expiration, and lockout rules but does not by itself determine the time windows during which logins are permitted. Option C is wrong because Session Timeout controls how long an existing idle session remains active before expiring, not whether a new login is allowed in the first place. Option D is wrong because IP Range Restrictions limit which IP addresses users may log in from, addressing location rather than the time-of-day scheduling that Login Hours enforces.