I'm still confused on how answer choice A can be right. If the proportion of car thieves who abandon the car before it is noticed to be stolen has decreased, then wouldn't that mean that car thefts has increased, which contradicts the first fact in the stim? If 5 years ago 50% of car thieves abandoned the car before it was noticed to be stolen but now only 25% of car thieves abandon the car before it is stolen, would that not mean that there are more car thefts now since less thieves are abandoning them? I think it is pretty reasonable to assume that a car that is never noticed to have been stolen would not be counted as a car theft.