Computer viruses can create problems for computer users because
they can interfere with radio transmissions
they are sometimes difficult to recognize
they improve the efficiency of your computer
all of the above

B is the answer please mark the brainliest

The best option for the question would be the second one.

"They are sometimes hard to recognize"

Viruses tend to be programmed to hide or blend in with your systems normal programming files. This also includes malware. Having a high end Anti-Virus would be a good option if your looking to protect your system.