Consider the following activities:1.Identification of narcotics on passengers at airports or in aircraft2.Monitoring of precipitation3.Tracking the migration of animalsIn how many of the above activities can the radars be used?

1. A

   Only one

   Only one. Radar is used in more than one of the listed tasks.

2. B

   Only two

   Only two. Weather radar monitors precipitation; wildlife radar tracks migrating animals. Narcotics screening is typically X-ray / trace / dogs, not radar as the tool.

3. C

   All three

   All three. Airport narcotics identification is not a radar job in this listing.

4. D

   None

   None. Two of the three use radar.

Summary. Official key is (b) only two. Weather radars monitor precipitation. Radars (and radar-like tracking) are used to follow bird and animal migration. Finding narcotics on passengers is imaging, sniffers and dogs — not radar as the named tool. So two activities, not three.