(a) Services performed for a person by an employee as an insurance agent or insurance solicitor are excepted from employment, if all such services performed for such person by such individual are performed for remuneration solely by way of commission.

(b) If all or any part of the remuneration of an employee for services performed as an insurance agent or insurance solicitor for a person is a salary, none of his services performed as an insurance agent or insurance solicitor for such person are excepted from employment, and his total remuneration (for example, salary, or salary and commissions) for such services is included for purposes of computing the tax.