19.△ABC为⊙O的内接三角形,若∠AOC=160°,则∠ABC的度数是( )
0 288736 288744 288750 288754 288760 288762 288766 288772 288774 288780 288786 288790 288792 288796 288802 288804 288810 288814 288816 288820 288822 288826 288828 288830 288831 288832 288834 288835 288836 288838 288840 288844 288846 288850 288852 288856 288862 288864 288870 288874 288876 288880 288886 288892 288894 288900 288904 288906 288912 288916 288922 288930 366461
| A. | 80° | B. | 80°或100° | C. | 100° | D. | 160°或20° |