Draw the structure of the xylene that will give only two mononitro derivatives.

Structure of meta xylene has been shown below.

Explanation:

Xylene is dimethyl substituted benzene. Among three possible isomers of xylene, only meta substituted xylene gives mononitration product at two different position. Mononitration is possible in meta-xylene due to synergistic effect of two o/p-orienting methyl groups. Synergistic effect refers that o/p-directing power of two methyl groups act together at a particular position. Structure of xylene as well as their two possible mononitro derivatives has been shown below.