Among the followings, which types of attack is an SSL stripping attack?

An SSL stripping attack requires attackers to persuade a victim to send traffic through them via HTTP while continuing to send HTTPS encrypted traffic to the legitimate server by pretending to be the victim. This is not a brute-force attack.
A Trojan attack would require malware.
A downgrade attack is a form of cyber attack in which an attacker forces a network channel to switch to an unprotected or less secure data transmission standard.