MRNA is a short lived form of genetic information that is used in transcribing the genetic information, hence it is not very useful for analysis since it is fragile and wrong transcriptions happen quite often. SNPs (Single Nucleotide Polymorphisms) are a form of genetic mutation; they are more frequent than most other mutations since a single transription error may lead to this. While SNPs are important in genetic analysis and getting information about causes of disease, they are not very helpful in determining your maternal lineage. Similarly, while nuclear DNA contains a large portion of our genetic information, half of it is from our fathers and half from our mothers, so the analysis becomes hazy very soon. Mitochondrial DNA instead is directly passed down from mother to her offspring since the embryo contains only the mitochondria of the ovary. Thus, studying differences between mitochondrial DNA, one can gain information about his maternal lineage and go back to Mitochondrial Eve, the person from which all living persons have gotten their mitochondria from. Thus, the correct answer is c.
The main objective of the Asteroid Redirect Mission was to develop deep space exploration capabilities needed in preparation for a human mission to Mars and other Solar System destinations per NASA's Journey to Mars flexible pathways.
