The organelle that moves material around the cell is the endoplasmic reticulum (ER).

Here's why:

* Rough ER: Studded with ribosomes, the rough ER is responsible for synthesizing proteins. These proteins are then packaged into vesicles and transported to other parts of the cell or secreted outside.

* Smooth ER: Lacks ribosomes and plays a role in synthesizing lipids, detoxifying drugs, and storing calcium ions. It also helps move materials around the cell.

Other organelles involved in transport:

* Golgi apparatus: Processes and packages proteins and lipids, often modifying them for specific functions before sending them to their final destinations.

* Vesicles: Small membrane-bound sacs that act like "delivery trucks," transporting materials around the cell and to the cell membrane for secretion.

So, while the ER is the main "highway" for moving materials around the cell, other organelles play important roles in the process.