Answer:
a) The computer at cyber cafe may have been infected with a virus which then infected her pendrive. When she connected the pendrive to her computer, the virus infected her own computer too.
b) Do not use public computers like the ones in cyber cafes since you do not know what might be on these computers (viruses or malware).
c) Vinita must download an anti-virus to help get rid of the viruses/malware that may be on her computer.