Which of the following statements regarding alkanes is not correct?

Chlorine has a much lesser tendency to replace tertiary hydrogen in preference to secondary or primary, statement B regarding alkanes is not correct.

As a result of lesser differences in activation energies for attacks at the 1°, 2°, and 3° positions, chlorination is less selective than bromination. At the 1° and 2° locations, propane is halogenated. As the chain propagation processes progress, several halopropanes are formed.

Hence, option B is correct.