CompTIA A+ Question F-22

An end user is designing a PC with a clear acrylic access panel to show off the insides. The user wants the inside to stay cool, but as dust free as possible. Which of the following would BEST meet this scenario?

A. Create a positive pressure air flow with unfiltered intakes and filtered exhausts
B. Create a positive pressure air flow with filtered intakes and unfiltered exhausts
C. Create a negative pressure air flow with unfiltered intakes and unfiltered exhausts
D. Create a negative pressure air flow with filtered exhausts and unfiltered exhausts