The transport system which is most affected by climatic factors is

Step 1: Analyze the question The question asks which mode of transport is most affected by climate (weather) factors such as fog, storms, wind, rain, visibility, and temperature.

Step 2: Explain the concept Different transport modes respond differently to climate:

• Water transport: Affected by storms, strong waves, fog, and seasonal changes in river levels (e.g., low water in the dry season on the Niger and Benue). It is affected considerably, but ships and boats can often adapt or wait out bad weather.
• Rail transport: Largely fixed on tracks and the least affected. Only extreme heat (track buckling) or flooding causes problems.
• Road transport: Affected by heavy rain, floods, erosion, and harmattan haze. Nigerian roads often become bad in the rainy season, but vehicles can usually still move with care.
• Air transport: Highly sensitive to weather. Low visibility from fog or harmattan dust haze, thunderstorms, strong winds, lightning, and turbulence can cause delays, diversions, or cancellations of flights. In Nigeria, harmattan haze often disrupts flights at airports in Kano, Lagos, and Abuja.

Step 3: Solve Comparing all four, air transport depends most on clear weather for safe takeoff, flight, and landing. A small change in visibility or wind can ground flights completely, whereas the other modes can usually continue, perhaps at a slower pace.

Step 4: Answer The transport system most affected by climatic factors is air transport, which is option D.

Tip: Remember "the higher and faster the transport, the more weather matters." Air transport depends on visibility and wind, so it ranks highest for climate sensitivity. Rail, being fixed on tracks, is usually the least affected.