John Has Been Using a Computer for the Past Six

Multiple Choice

John has been using a computer for the past six months, loading a lot of software and media on the computer. He has never connected his computer to the Internet. For the past few weeks, his computer has been slow to respond to any commands to open a file or copy files. Which of the following options could make his computer faster?

A) Disk Defragmenter
B) Antivirus software
C) Firewall software
D) Upgrading the processor