Concept:The Public Service Commission manages civil service personnel matters, not taxation.
Explanation:The Public Service Commission serves as an advisory body.
It is responsible for the welfare of personnel.
It also handles the discipline of personnel.
However, imposing income tax is not among its functions.
Income tax is imposed by the government revenue authorities.
So, the only function that the Public Service Commission does not perform is imposition of income tax.
Answer:B. imposition of income tax