D. only in the nucleus. DNA or (deoxyribonucleic acid) is what makes you... YOU! All of your traits (Hair color, Eye color, The shape of your ears, Cancer risk, SKIN COLOR, etc.) But DNA is only housed in the nucleus of the cell, so the nucleus is the only place the transcription of the melanin gene could take place.
C is your most responsible answer because if they provide enough evidence to support that it fights lung cancer then that one will be the best one or effective