Answer:
B. Computer's resolution has been set too low
Explanation:
A. Font size has been set too high.
B. Computer’s resolution has been set too low.
C. Refresh rate of the video card is out of sync with the monitor’s refresh rate.
D. ClearType setting is enabled.
From the given options; if the font size has been set too high, the effect is on the texts and not icons. If the video card is out of sync there will be little or no display at all.
So, the correct option is Computer's resolution has been set too low.