The correct option is A Rainfall
Rain
gauge can accurately measure the rainfall without any loss due to evaporation.
It is an instrument used for determining the depth of precipitation that occurs
over a unit area. Thus, it measures rainfall. One litre of rainfall per meter
squared is equivalent to one millimeter of measured precipitation. A funneled
aperture of 150-170 cm is found in standard rain gauges. They are designed as a
simple passive collector. A graduated measuring glass is used for determining
the amount of precipitation.