To solve this problem, we need to identify which organelles are not part of the endomembrane system.$\newline$The endomembrane system includes organelles that are involved in the synthesis, processing, and transport of proteins and lipids.$\newline$Let's analyze each option:$\newline \bullet$A. Mitochondria:$\newline$ - Mitochondria are not part of the endomembrane system. They are involved in energy production through cellular respiration.$\newline \bullet$B. Endoplasmic Reticulum:$\newline$