The correct option is
A A- 2, B- 3, C- 4, D- 1
Palynology is the study of plant pollen, spores and certain microscopic plankton organisms. Oncology is the study and treatment of tumours and cancer.
Phycology is the scientific study of algae.
Sericulture is the production of silk and the rearing of silkworms for this purpose. Hence, option A is correct answer.