The following compound is the positional isomer but not the chain isomer of ‘C’

A  is  CH3−CH2−CH=CH2  through  E2  mechanism;A→BCH3−CH2−CH=CH2→slowH+CH3−CH2−C+H−CH3more stable2o+CH3−CH2−CH2−C+H2less stable1oCH3−CH2−C+H−CH3→fastBr−CH3−CH2−CHBr−CH3BB→CCH3−CH2−CHBr−CH3→ alc.KOHCH3−CH=CH−CH3CSaytzeffmajor+CH3−CH2−CH=CH2Hoffmannminor