The `sendfile` system call optimizes static file serving (e.g., Nginx) by:

1. A It proactively compiles the entire static file directory into the application's executable binary to eliminate the need for any high-latency disk-based read operations.
2. B It utilizes a specialized, high-performance Javascript runtime inside the kernel to dynamically evaluate and optimize the file's binary structure before transmission.
3. C It relies on a specialized client-side header that instructs the browser to download the file directly from the nearest globally-available persistent CDN cache.
4. D It enables the kernel to transfer data directly from the Disk Page Cache to the Network Socket Buffer, bypassing the expensive step of copying data into user-space memory.