How can a computer become infected with a virus through malicious websites? 

a. Computers become infected with viruses when they encounter hardware failures. 

b. Computers become infected with viruses when they reach their maximum storage capacity. 

c. Computers become infected with viruses when they are connected to public Wi-Fi networks. 

d. Visiting malicious websites that host infected content or clicking on malicious advertisements can expose a computer to drive-by downloads, leading to virus infection.