A computer virus is a malicious software program that can replicate itself and infect other computers. Computer viruses can be transmitted through various means, but there is one option in the list that is not a way for a computer virus to be transmitted: formatting of documents.
Formatting of documents is a process of changing the appearance and layout of a document, such as adjusting the font, margins, or spacing. It does not involve the transfer of any executable code or software, which is necessary for a virus to infect a computer.
On the other hand, email, external storage devices, and the internet can all be used as vectors for transmitting computer viruses. Email attachments, for example, can contain infected files that, when opened, can infect the recipient's computer. External storage devices, such as USB flash drives, can carry viruses that can infect computers when the device is plugged in. The internet can also be a source of viruses, as they can be downloaded or installed from websites or through malicious links.
To prevent virus infections, it is important to keep your computer's antivirus software up-to-date, avoid opening suspicious email attachments, and be careful when downloading files from the internet or using external storage devices.