A: Root Cause Analysis: Looking at the given vulnerable code line and its context, the CWE-787 (out-of-bounds write) vulnerability exists in the code because the `strncpy` function is used to copy the value of the `pszFileName` parameter into the `szFileName` buffer. However, the size of the `szFileName` buffer is not checked before copying, which can lead to a buffer overflow if the length of the `pszFileName` parameter is larger than the size of the `szFileName` buffer minus 5. This can result in writing data beyond the bounds of the `szFileName` buffer, causing a buffer overflow vulnerability, which is CWE-787.