Claim: hybrid vehicles eliminate air pollution which counterclaim makes a straw man fallacy? a. people who buy hybrid vehicles are idiots b. forcing people to buy hybrid vehicles is wrong c. hybrid vehicles are usually quite expensive d. there are more practical ways to eliminate pollution

Option B. "Forcing people to buy hybrid vehicles is wrong" is a counterclaim that makes a straw man fallacy.

A straw man fallacy occurs when an argument refutes a point that the opposing side did not make. A straw man fallacy does not discuss the original argument but instead argues against another, "fake" argument that exaggerates an issue.

Option A. is a personal attack. Options C. and D. could conceivably be counterpoints to the original argument. 

However, Option B. is refuting an argument the original statement is not making. The original argument says only the hybrids help eliminate air pollution. No one said anything about forcing people to buy them -- this is an exaggerated claim. Therefore, Option B. is a straw man fallacy.