# Which one of the following is a narrow spectrum antibiotics ?

$(a)\;\text{tetracycline} \\ (b)\;\text{penicillin} \\(c)\;\text{streptomycin} \\ (d)\;\text{Chloramphemical}$

Broad spectrum antibiotics are medicines effective against number of harmful micro-organisms
Penicillin has arrow spectrum.
Hence b is the correct answer.