Task: Class Definition Understanding (ontology: Sciences/Biology)

Which of the following definitions best describes '(3R)-3,6-diammoniohexanoate(1+)'?

A. Conjugate acid of (3S,5S)-3,5-diaminohexanoic acid.
B. An amino-acid cation obtained by deprotonation of the carboxy group and protonation of the two amino groups of (3R)-3-methyl-D-ornithine; major species at pH 7.3.
C. An amino-acid cation comprising psicosyllysine having a deprotonated carboxy group and both amino groups protonated; major species at pH 7.3.
D. An amino-acid cation that is the conjugate acid of 3,6-diaminohexanoic acid resulting from protonation of both amino groups and deprotonation of the carboxy group; major species at pH 7.3.

Answer: An amino-acid cation that is the conjugate acid of 3,6-diaminohexanoic acid resulting from protonation of both amino groups and deprotonation of the carboxy group; major species at pH 7.3.