The correct option is B n- Octane
Boiling point of alkane increases with molar mass. Among isomeric alkanes, branching will have lower boiling point because it decrease the overall surface area. This leads to a reduction in the intermolecular forces (London dispersion forces), thereby decreasing boiling point. Therefore, n - Octane has highest boiling point, higher than 2, 2, 3, 3- Tetramethyl butane (an isomer of n - Octane).