"Although electric vehicles (EVs) are widely promoted as the ultimate solution to urban air pollution, their environmental footprint is not entirely clean. The manufacturing process of lithium-ion batteries requires massive energy inputs and relies heavily on mining rare minerals. This raw material extraction often results in significant ecological damage and water contamination in nearby communities. Thus, without cleaner battery production methods, the green status of EVs remains questionable."
Question: What is the main idea of this passage?
(A) Lithium-ion batteries are the most efficient power source for vehicles.
(B) Electric vehicles have environmental drawbacks associated with battery production.
(C) Mining rare minerals is a lucrative industry globally.
(D) Urban air pollution can only be cured by transitioning to public transit.