Ans: A
I is true. Note that the sum of all exterior angles of all polygons is $360^\circ$. Therefore, each exterior angle of a regular 12-sided polygon is $360^\circ\div 12 = 30^\circ$.
I is true. Note that the sum of all exterior angles of all polygons is $360^\circ$. Therefore, each exterior angle of a regular 12-sided polygon is $360^\circ\div 12 = 30^\circ$.
II is true. Note that the sum of all interior angles of a 12-sided polygon is $(12-2)\times180^\circ=1~800^\circ$. Then each interior angle is $1~800^\circ\div 12 = 150^\circ$.
III is false. There are altogether 12 axes of reflectional symmetry.
