Which of the Following Molecules Contain the Same Functional Groups

Which of the following molecules contain the same functional groups? $$\mathrm { CH } _ { 3 } \mathrm { CH } \left( \mathrm { NH } _ { 2 } \right) \mathrm { CH } _ { 3 } \quad \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { CH } _ { 2 } \mathrm { NH } _ { 2 } \quad \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { CONH } _ { 2 } \quad \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { NHCH } _ { 3 }$$
$$\mathrm { I }\quad\quad\quad\quad\quad\quad\mathrm { II }\quad\quad\quad\quad\quad\quad\mathrm { III }\quad\quad\quad\quad\quad\quad\mathrm { IV }$$

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