Which one is a broad spectrum drug?

The broad spectrum drug among the options is 1. Chloramphenicol.

Broad-spectrum drugs are antibiotics that can kill a wide range of bacteria. Chloramphenicol is a broad-spectrum antibiotic that is used to treat a variety of infections, including pneumonia, typhoid fever, and meningitis.

Chloroquine, chloroxylenol, and plasmoquine are not broad-spectrum drugs. Chloroquine is used to treat malaria, chloroxylenol is used as an antiseptic, and plasmoquine is used to treat babesiosis.