In Which of the Following Ions Does Carbon Have a Formal

Multiple Choice

In which of the following ions does carbon have a formal charge? $\mathrm { CH } _ { 3 } \mathrm { OH }\quad$$\mathrm { NaCH } _ { 3 }\quad$$\mathrm { CH } _ { 3 } \mathrm { CO } _ { 2 } -$
I $\quad\quad\quad\quad\quad$ II $\quad\quad\quad\quad$ III

A) I
B) II
C) III
D) None of the above