If lawmakers generally mandate penalties that correspond to the harm that they think results from a crime, then it’s likely the lawmakers in these jurisdictions consider theft and bribery equally harmful, since the penalties for both are the same.

The argument addresses how lawmakers set penalties for crimes, not how they decide if an act is illegal. Instead of (B), we need to know whether lawmakers assess the level of harm resulting from an act in determining the penalty for that act.

This suggests that a very harmful case of theft or bribery would lead lawmakers to increase the penalty. But the author is focusing on the harm of theft and bribery overall, not just extreme cases.

The author only discusses how much harm lawmakers think bribery and theft cause; it doesn’t matter how much they actually cause. Even if they cause equal harm, this doesn’t help to determine whether lawmakers mandate penalties based on how much harm they think a crime causes.

The author doesn’t mention anything about crime being effectively deterred. Instead, we need to know whether lawmakers actually “mandate penalties for crimes that are proportional to the harm resulting from those crimes” in the first place.