The correct option is
B 3−methylphenol
IUPAC nomenclature of m−cresol
Structure of
m−cresol is:

Alcohol is given higher priority over methyl group. So, it is named by considering that
−OH group is attached to
C−1.
So,
IUPAC name of
m−cresol will be
3−methylphenol
Analysing the options
Option (A)
3−methylphenol represents the
m−cresol.
Option (B)
Structure of
3−chlorophenol is shown below:

Obviously, it does not represent
m−cresol.
Option (C)
Structured of
3−methoxyphenol is shown below:

It too does not represent
m−cresol.
Option (D)
Structure of
benzene−1,3−diol is shown below:

It too does not represent
m−cresol, it is resorcinol. So, the correct answer is option
(A).