Which of the following descriptions is true about a static NAT?

Many-to-many mapping does not describe any standard NAT type - NAT types are defined as one-to-one (static), one-to-many (PAT/overload), or many-to-one (dynamic pool).

One-to-many mapping describes PAT (Port Address Translation), also called NAT overload, which maps many private addresses to a single public IP using port differentiation.

Many-to-one mapping describes dynamic NAT with overload or PAT, where multiple internal hosts share a single public IP, not static NAT.

Static NAT maps exactly one private (inside local) IP address to exactly one public (inside global) IP address in a fixed, manually configured relationship. This one-to-one mapping persists regardless of traffic and is commonly used to allow external hosts to reliably reach internal servers such as web or mail servers using a consistent public address.