It's high sensitivity I believe
A. they tend to be unspecialized.
B. Subgroups
<span>When constructing a dichotomous key, the first step is to look at the group of objects or organisms and separate them into two groups based on a single distinguishing characteristic. Then continue to separate each of the groups until each object has its own separate set of characteristics.</span>
Pretty sure the correct answer would be Choice A
Nucleic acids / aka nucleotides