Step 1: Understand robot arm configurations.
Robotic arms are often represented using notations to describe their link and joint configurations:
- LLL denotes a robot with three links and three revolute joints (revolute joints allow rotational movement).
- The other options describe various combinations of joints and links, but LLL is the standard notation for a robot with joined arm configurations, specifically with three links and three revolute joints.
Step 2: Conclusion
The correct notation for a robot with a joined arm configuration is LLL.
Final Answer:
\[
\boxed{\text{LLL}}
\]