The correct option is B Palynology
Pollen grains are haploid microspores produced in higher plants like gymnosperms and angiosperms. In higher plants the pollen grains produce male gametes by the process of mitosis. The study of pollen grains is called palynology. It is useful in forensics, evolutionary studies etc. The important pollen characters that are studied are number, position and character of aperture, encrustations of exine, viability, longevity etc.