Male- private parts are different, Males have sperm that contributes to the reproduction process, males give 23 chromosomes like female's
Female- private parts are different, female's contributes eggs to the reproduction process, female's give 23 chromosomes like male
The answer to this question is the sacrum. The sacrum is a triangular bone that forms the base of the spinal column. This bone has a vital role in the skeletal system and also supports the weight of the upper body of a person and this bone and many nerves are inside the sacrum.
So abiotic means nonliving, so the only abiotic option is B. the gravel on the bottom of the aquarium.