Which feature distinguishes employment under the CLT (celetista) regime — used by NAV Brasil employees — from the statutory (estatutário) regime of tenured public servants?

1. CLT employees are governed by labor law (Consolidação das Leis do Trabalho) acquired by public hiring examination or process, without the constitutional tenure (estabilidade) of statutory servants
2. CLT employees enjoy life tenure identical to art. 41 of the Constitution
3. CLT employees cannot be hired through public examinations
4. Statutory servants are paid exclusively by commissions, unlike CLT employees