One advantage of allele-specific oligonucleotide (aso)-based over rflp-based detection of human genetic disease is that

An allele-specific oligonucleotide (ASO) is a tiny piece of artificial DNA balancing to the order of an adjustable target DNA. It performs as an enquiry for the occurrence of the target in a Southern blot assay or Dot blot assay. One advantage is the mutation need not be positioned within a limit enzyme recognition site. 

dna is made up of six smaller molecules -- a five carbon sugar called deoxyribose, a phosphate molecule and four different nitrogenous bases (adenine, thymine, cytosine and guanine).

the answer is c. altitude. hope this ! #brainiac