Will it be right if B change to "A smaller 'proportion' of domestic cats than wild cats have a high muscle-to-fat ratio."

Hey, quick question about this sentence: "All self-driving cars must be programmed to ensure not only the safety of its passengers but of other people on the road as well."

Why isn't "must be programmed" part of the sufficient condition, similar to how "after a week" is part of the sufficient condition in "Anyone infected by the virus will, after a week, produce antibodies"? Shouldn't it be: self-driving cars + programmed → ensure safety?