Premise: The cost-effective solution to the problem of airport congestion and pollution it causes is to provide high-speed train service between major cities in China, lying 300 to 800 kilometers apart.

Conclusion: The plan would cost far less than the expansion of existing airports and would reduce the number of airplanes clogging airports and polluting the air.

Option A - Incorrect:
This is not enough for the opposition to use as a piece of evidence in objecting to the plans because their intent is more on the expansion of existing airports and not significant repairing airports.

Option B - Correct:
In a way to discredit the proposed plan by the opposition, high-speed trains solution plan would cause more pollution per passenger than planes will do because of the large number of occupants a train can carry as compared to planes. Thereby, enabling the passengers to direct contact with pollution that can pose more hazards to their health. This evidence holds a strong basis to disapprove the proposed plan. Hence, this option is correct.

Option C - Incorrect:
This claim is irrelevant to the argument at hand.

Option D - Incorrect:
This claim cannot hold any strong basis to be used as evidence by the opposition as it holds no fact and doesn't sound logical enough.

Option E - Incorrect:
We cannot validate this claim from the passage as there is no such information to back it up.