The dipeptide, Gly. Ala has structure -

• A. \[{{H}_{3}}\overset{+}{\mathop{N}}\,C{{H}_{2}}\overset{O}{\mathop{\overset{||}{\mathop{C}}\,}}\,NH\underset{C{{H}_{3}}}{\mathop{\underset{|}{\mathop{C}}\,}}\,HC{{\bar{O}}_{2}}\]
• B. \[{{H}_{3}}\overset{+}{\mathop{N}}\,\underset{C{{H}_{3}}}{\mathop{\underset{|}{\mathop{C}}\,}}\,H\overset{O}{\mathop{\overset{||}{\mathop{C}}\,}}\,NH\underset{{}}{\mathop{\underset{{}}{\mathop{C}}\,}}\,{{H}_{2}}C{{\overset{-}{\mathop{O}}\,}_{2}}\]
• C. \[{{\overset{-}{\mathop{O}}\,}_{2}}C\underset{C{{H}_{3}}}{\mathop{\underset{|}{\mathop{C}}\,}}\,HNH-\overset{O}{\mathop{\overset{||}{\mathop{C}}\,}}\,-\underset{{}}{\mathop{\underset{{}}{\mathop{C}}\,}}\,{{H}_{2}}\overset{+}{\mathop{N}}\,{{H}_{3}}\]
• D. \[{{\overset{-}{\mathop{O}}\,}_{2}}CC{{H}_{2}}NH-\overset{O}{\mathop{\overset{||}{\mathop{C}}\,}}\,\underset{C{{H}_{3}}}{\mathop{\underset{|}{\mathop{C}}\,}}\,H\overset{+}{\mathop{N}}\,{{H}_{3}}\]