please help with question 7 and question 8

Question 7 Not yet answered Marked out of 1.00 Flag question If set A={0,2,4,6,8), B={0,1,2,3,4), C={0,3,6,9). What is AUBUC Select one: O a. {2,3,4,6,8} O b. {0, 1,2,3,4,6,8,9} O c. {1,2,3,4,6,8,9} O d. {0, 1,2,3,4,6,9} Question 8 Not yet answered Marked out of 1.00 Flag question A compound proposition where all the values are neither True nor False is referred to as? Select one: a. Bi-conditional O b. Contradiction O c. Tautology O d. Contigency