Answer:b) Caenorhabditis
Step-by-step explanation:
The C.elgans is a species of Caenorhabditis. It is a namatode which can be male or hermaphrodite. It lays 1000 of eggs which can be used for the purpose of research studies. These worms share common genes and molecular pathways like in humans.
Many of the genes present in C. elegans have functional counterparts as that of humans which makes them useful for determining the cause of human diseases. The mutant forms of genes of C.elegans can be used for screening the thousands of drugs. The genes have been used to determine the effects of ageing in humans, cancer, diabetes and other diseases.
Due to above reasons the C.elegans are considered as model organisms.