Solution

We must identify which statements are the most logical conclusions that can be drawn from the main statement: "Ministers arrived at the public function in their cars."

Analysis of Statements:

• (b) Minister have official cars in general: The fact that they arrived in cars for a public function strongly implies that they have cars (likely official ones) for such duties. This is a reasonable conclusion.
  
• (c) Minister usually participate in public functions: Their presence at a public function suggests that this is a typical part of their role. This is also a reasonable conclusion.
  
• (a), (d), (e): These are incorrect. We cannot be certain that all ministers are rich (a), that only rich ones have cars (d), or that only ministers have cars (e). These are unsupported assumptions or fallacies.
  

Conclusion:

The most logical and direct conclusions are (b) and (c).