James, a student, accessed a ticket booking portal for a flight ticket to reach his university, which is located in another state. As he does not have an account in that ticketing platform, he got a pop$-$up message informing him to access the website through any popular social media account credentials. Identify the authentication method demonstrated in the above scenario.

Biometric authentication

Two$-$factor authentication

Single sign$-$on $($SSO$)$ authentication

Smart card authentication