CompTIA Security+ (SY0-501) — Question 634

Which of the following implements two-factor authentication on a VPN?

Answer options

• A. Username, password, and source IP
• B. Public and private keys
• C. HOTP token and logon credentials
• D. Source and destination IP addresses

Correct answer: A

Explanation

Option A is correct because it combines something the user knows (username and password) with something that can be tracked (source IP), which is characteristic of two-factor authentication. The other options do not effectively combine these two authentication factors; for example, B refers to key-based encryption, C involves a token but lacks additional factors, and D simply describes network addressing without authentication.