The number of isomers that can be obtained theoretically on monochlorination of `2`-methylbutane is:

The number of structural isomers that can be obtained theoretically on monochlorination of 2-methylbutane is:

Number of structural isomers which can be obtained theoretically on monochlorination of 2-methylbutane is

Number of isomers which can be theoreticaly obtained on monochlorination of 2- methylbutane is :

Number of structurl isomer which can be theoretically obtained on monochlorination of 2- methylbutane is_