Answer:

A. 5,6,7

B. 0,1,2,3

C. none

D. 0-7

Step-by-step explanation:

A. x>4: 5+12<20 = 17<20 ✓

B. x<4: 3+12<20 = 15<20 ✓

C. x>8: 9+12<20 = 21>20

D. x<8: 7+12<20 = 19<20 ✓