Which of following is not a free radical -HOC1

Which of following is not a free radical -
a) H202
b) (M?
c) Superoxide anion
d) HOC1-
Correct Answer - D
Ans. is ‘d’ i.e., HOC1– [Ref Principles in medical pathology p.
391]
Free radicals are chemical species that have a single unpaired
electron in the outer orbit. Most of these are partially reduced
reactive oxygen forms that are produced as an unavoidable
byproduct of mitochondria! respiration - also known as reactive
oxygen species.
The most important are hydrogen peroxide (1120), Superoxide anion
(02) and hydroxyl radical (OH)