Critical Reasoning (CR) | Re: If only the people using a carpool and only small cars with

Why not option A?
B says many people don't use carpool. But the author says that if only 'people who use carpool were allowed to use' which implies many people uses carpool but the number of large car users is also huge.
Option E states that roads can't cope up. But here author talks about the comfort of people rather than strength of roads.
C, D feels irrelevant here. Not all roads are overcrowded and speed isn't going to solve the issue.

Correct me if I'm wrong.
Thank you
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