Question

what is the international emergency signal for distress?
a marking an x in the snow, grass, or sand
b flashing a mirror
c signaling with a whistle
d three repeats of any signal

Explanation:

The international emergency signal for distress is three repeats of any signal. This is a widely - recognized standard. Marking an X is not the international distress signal. Flashing a mirror can be a way to signal but is not the specific international emergency distress signal in the general sense. Signaling with a whistle is also not the defined international emergency distress signal. The key is the repetition of three times which is a universal code for distress.

Answer:

D. three repeats of any signal