Answer:
I'm assuming it 1
Step-by-step explanation:
I'm guessing this question is about medieval Europe so it's most likely one. because first of all it's correct in medievil Europe living conditions weren't as good as ours today and life expectancy for lower. in addition to this their Healthcare system was terrible most doctors stuck leeches to heal people. also we know it's most likely not 2 because the crusades did fail many times but it wasn't enough to shorten life expectancy. and weknow it's probably not 3 and 4 so that's is why 1 is the answer