Which structure is responsible for transporting semen outside of the body? a.scrotum b.urethra c.sperm duct d. fallopian tube

I strongly believe the answer is urethra. The urethra is the tube that carries urine from the bladder to outside of the body. In males, it has the additional function of releasing semen with the sperms to the outside during ejaculation. The sperms are transported by the vas deferens from the epididymis where maturation of the sperms occurs 

The answer to your question:

Habitat is a set of the place of environmental conditions in which particular organism lives and adapt the situation accordingly. A niche is nothing but an idea or role played by organisms that how they can live in an environment including their diet, shelter, etc. Mainly niche is concerned with the factor of gaining energy by organisms and supplying it to other, in the ecosystem.