Which proun agrees with the antecedent in the sentence? somebody dropped there. her, his or her, his, their

It's their because you're describing someone's action

Okay, biology isn't exactly my strongest subject (it never has been), but i'm pretty sure the answer is nucleotides. dna is made up of nucleotides. each nucleotide contains a phosphate group, a sugar group, and a nitrogen base. there are four different nitrogen bases: adenine (a), thymine (t), guanine (g), and cytosine (c). a always pairs with t, and g always pairs with c.