Four friends A, B, C, and D, who are from different families, meet at a party. One of them is the doctor A says, " B is a doctor".B says, "I am a doctor."C says, "D lies."D says, "B lies."If only one of them is laying, then find out who the doctor is.

Four friends A, B, C, and D, who are from different families, meet at

1.	Four friends A, B, C, and D, who are from different families, meet at a party. One of them is the doctor A says, " B is a doctor".B says, "I am a doctor."C says, "D lies."D says, "B lies."If only one of them is laying, then find out who the doctor is.
A.	c
B.	b
C.	d
D.	a
Answer» C. d