The correct matching of instruments with their functions is as follows:
- (A) Eppley Spectral Radiometer (II - Photosynthetically Active Radiation): This instrument measures Photosynthetically Active Radiation (PAR), the portion of the solar spectrum (400–700 nm) used by plants for photosynthesis.
- (B) Kipp Radiometer (IV - Diffused radiation): Also known as a Kipp \& Zonen pyranometer, it measures diffused solar radiation, which is sunlight scattered by the atmosphere, often used in meteorological studies.
- (C) Pyradiometer (I - Both short and long wave radiation): This device measures total radiation, including both shortwave (solar) and longwave (infrared) radiation, used for studying energy balance in meteorology.
- (D) Spectrophotometer (III - Wavelength of light): This instrument analyzes the intensity of light at specific wavelengths, used in laboratories to study material properties or chemical compositions.
Thus, the correct pairing is (A) - (II), (B) - (IV), (C) - (I), (D) - (III), making option (2) correct.