Complementary angles are those angles that together form the angle of measure 90°.
Supplementary angles are those angles that together form the angle of measure 180°.
1. m∠DGB+m∠EGA≠90° - this option is false.
2. m∠DGB+m∠CGB=180° - this option is true.
3. m∠CGB+m∠AGD≠90° - this option is false.
4. m∠EGA+m∠EGB≠90° - this option is false.
5. m∠EGD+m∠CGB≠180° - this option is false.
Answer: correct choice is 2.