Which is the best antiknock compound or Which one of the following substances is used as an antiknock compound [CPMT 1974, 81, 99, 2000;RPMT 2002; CBSE PMT 1996; KCET (Med.) 2000 MP PET 1985, 87, 97, 2001; MP PMT 1994, 96; AIIMS 2000]

Which is the best antiknock compound or Which one of the following sub

1.	Which is the best antiknock compound or Which one of the following substances is used as an antiknock compound [CPMT 1974, 81, 99, 2000;RPMT 2002; CBSE PMT 1996; KCET (Med.) 2000 MP PET 1985, 87, 97, 2001; MP PMT 1994, 96; AIIMS 2000]
A.	Lead tetrachloride
B.	Lead acetate
C.	Zinc ethyl
D.	Tetraethyl lead (TEL)
Answer» E.