Which of the Following Molecules Contain the Same Functional Groups

Multiple Choice

Which of the following molecules contain the same functional groups? $$\mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { OH } \quad \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { OCH } _ { 2 } \mathrm { CH } _ { 3 } \quad \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { CH } _ { 2 } \mathrm { OH } \quad \mathrm { CH } _ { 3 } \mathrm { CH } ( \mathrm { OH } ) \mathrm { CH } _ { 3 }$$
$$\mathrm { I }\quad\quad\quad\quad\quad\quad\mathrm { II }\quad\quad\quad\quad\quad\quad\mathrm { III }\quad\quad\quad\quad\quad\quad\mathrm { IV }$$

A) I, II, III
B) I, II, IV
C) II, III, IV
D) I, III, IV