Find the odd mode of transport (medium of travel): Select the one designed for water, while the others are for land.

Introduction / Context:
Transportation items can be grouped by the physical medium: land, water, or air. Recognizing the intended medium gives a decisive basis to choose the outlier.

Given Data / Assumptions:

• Bus: land vehicle operating on roads.
• Scooter: land vehicle (two-wheeler) for roads.
• Cycle: land vehicle (bicycle) for roads/paths.
• Boat: watercraft designed to float and move on water.

Concept / Approach:
Classify by medium: land vs water. Three items are land vehicles; one is a watercraft. That categorical difference is unambiguous and independent of propulsion method.

Step-by-Step Solution:

Verification / Alternative check:
Consider design constraints: wheels and tires imply land friction/traction; hulls imply buoyancy for water.

Why Other Options Are Wrong:
They are all road-going vehicles, sharing the same core operating environment.

Common Pitfalls:
Do not be misled by powered vs unpowered distinctions (scooter vs cycle). The medium criterion is stronger.

Final Answer:
Boat