Answer:
A plasmid
Explanation:
A plasmid is an extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. -Wiki
Letter D would be likely it
Answer:
I believe it would be the one orbiting above the atmosphere or on Venus
Explanation:
There are no artificial/man-made interferences and being outside of the Earth's atmosphere more starlight can reach the observatory.