In robotics and control, if a robot modifies its trajectory in real time based on sensory feedback and changing external conditions, it is considered:

Introduction / Context:
Robot classifications often hinge on feedback and autonomy. A key distinction is whether the system can sense its environment and alter actions accordingly, versus executing a predetermined path with no adjustments. The ability to adapt trajectory speaks to intelligence and closed-loop behavior.

Given Data / Assumptions:

• The robot alters its path in response to external conditions.
• Sensing and feedback are present during motion.
• We are choosing the best descriptor among common robotics terms.

Concept / Approach:

Altering trajectory based on sensory input implies an intelligent system employing perception, planning, or control algorithms that adjust commands. This contrasts with open-loop or non-servo systems, which lack feedback-based correction and cannot compensate for disturbances. While mobility refers to the capability to move, it does not imply adaptivity.

Step-by-Step Solution:

Verification / Alternative check:

Standard robotics texts associate intelligent behavior with sensing, planning, and feedback control that change motion online, e.g., obstacle avoidance and trajectory replanning.

Why Other Options Are Wrong:

Mobile: Can move, but may still be preprogrammed and non-adaptive.

Open loop / non-servo: No feedback; cannot adjust to external changes.

None: Incorrect because ‘‘intelligent’’ captures the described behavior.

Common Pitfalls:

Equating servo control alone with intelligence; while servoing is a mechanism, the question emphasizes adaptive, condition-driven changes indicating intelligent control.

Final Answer:

intelligent