Therefore: -t True or False? Explain a) X being a square is a necessary condition for x being a rectangle 5. b) X being greater than 15 is a sufficient condition for X being less than 20 On the island of knights (who always tell the truth) and knaves (who always lie), you meet three natives, A, B, and C, who address you as follows: 6. A: All of us are knaves. B: Exactly one of us is a knight. What are A, B, and C