Which of the following software displays advertisements, whether or not the user has consented?

A Trojan horse is malicious software disguised as legitimate software that, once installed, performs harmful actions beyond displaying ads, such as creating backdoors or stealing data.

A honeypot is a security mechanism designed to lure and trap cyber attackers, collecting information about their techniques, not to display advertisements.

Spyware monitors user activity and collects personal information without consent, often for marketing or data brokering, but its primary function is not to display advertisements directly, though it can contribute to targeted ads.

Adware is software that displays unwanted advertisements on a user's computer, often bundled with legitimate software or downloaded without clear disclosure, serving ads whether or not the user has consented.