When you turn on the fast time constant (differentiator) control of a radar it will __________.

Correct Answer: Option D — reduce clutter over the entire PPI by shortening the echoes

The Fast Time Constant (FTC) circuit, or differentiator, acts as a high-pass filter. It shortens the duration of radar echoes, which effectively breaks up large areas of clutter caused by rain or snow. By shortening the echoes, it allows the operator to distinguish individual targets that would otherwise be masked by precipitation.