Hi William!
One of the things that makes this question so hard for folks is that they take "almost universally accepted" to mean "can't be over-ridden." But this isn't actually the case. For one thing, that "almost" gives you some wiggle room. "Almost universal" won't ever translate into an absolute on the LSAT.
But more fundamentally, a thing being universally accepted doesn't imply that it cannot be over-ridden. And for good reason! Think about a courtroom scenario in which a man is being charged with driving his car on the sidewalk. Let's say a traffic light camera caught him in the act. Illegal? Definitely. It's universally accepted that driving on the sidewalk is illegal. But is this worthy of conviction? Well, that depends. What if the camera also captured footage of a child running in the street in front of the car? If driving on the sidewalk was the only way to avoid running over the child, the driver was faced with two conflicting absolute legal imperatives: don't drive on the sidewalk and don't run over children. He couldn't satisfy them both, so he had to choose.
The same logic applies to this question. Even though it's almost universally accepted that we should project family members from harm, other universally-accepted obligations might outweigh the duty to family in certain situations. The Editorialist fails to consider that possibility, and that's why answer B is correct.
Hope this helps!