Question

Where are rain gauges located?

Answer 1

I believe the answer is A

Answer 2

The rain gauge is an instrument used by meteorologists to measure the amount of precipitation in a particular region in a particular amount of time.  

The rain gauge is placed on the ground in order to collect the rain or the precipitation sample. The rain gauge is labelled with the quantities, which can be used to measure the amount of precipitation.

So, the correct answer is option (a). on or near the ground.