The call to tech support was fairly routine. a first-time computer user had purchased a brand new pc two months ago and it was now operating much more slowly and sluggishly than it had at first. had he been accessing the internet? yes. had he installed any "free" software? yes. the problem is likely to be a(an)
(a) virus.
(b) zero-day attack.
(c) denial of service attack.
(d) dictionary attack.

A) virus.

Explanation:Virus is the piece of code that gets into the computer system and other devices to invoke the malicious activities such as slow processing, corrupting the data, disable some functions etc.The virus may get invoke in the system through internet sites,software and other means and spreads in the replicating way over the system.Virus can be eliminated by using the anti-virus software.

(A) Virus.

Explanation:

Virus can spread through by internet through emails,downloading files,ans spam links.There are many sources form where the virus can spread via internet.Free softwares also contain viruses.Viruses are the main reason behind the system not performing well. Viruses alters the way the computer operates.

given the options, i would say your best bet is c. the modem supports up to 56 kbps, which is too low for video streaming. dial up modems use actual phone lines, which only can go up to 56 kbps as that's more than sufficient for traditional phone calls. this is also the reason why when a dial-up modem connects, you hear all those sounds. it's literally using the phone line to establish a connection.

try a gofundme or ask your family for money slowly and slowly then save it or do trades on craigslist. that's all i know