Final answer:
For an LTI system to be stable and causal, it must meet two conditions: stability and causality. Stability ensures that bounded input produces bounded output, while causality ensures that the current output depends only on past and present inputs.
Step-by-step explanation:
To ensure stability and causality in a Linear Time-Invariant (LTI) system, two conditions must be met.
Firstly, the system must be stable, meaning that any bounded input to the system produces a bounded output. This can be achieved when the poles of the system's transfer function have negative real parts.
Secondly, the system must be causal, which means that the output of the system at any given time depends only on past and current inputs. In other words, the system cannot have any future inputs affecting the current output.