REPEATED REASONING In Exercises $21-24,$ select the angles of rotational symmetry for the regular polygon. Select all that apply.
A. $30^{\circ}$
B. $45^{\circ}$
C. $60^{\circ}$
D. $72^{\circ}$
E. $90^{\circ}$
F. $120^{\circ}$
G. $144^{\circ}$
H. $180^{\circ}$