Hundreds of Years Ago,the Highest Death Rates Were Among Children

Hundreds of years ago,the highest death rates were among children.By the beginning of the twentieth century,the highest death rates were among the elderly because:

A) child labor laws restricted children's entry into the workplace where many deaths occur
B) children were eating healthier diets and there was more emphasis on cleanliness and were therefore less likely to die young
C) AIDS was most fatal for young children, but today it is more fatal for elderly people
D) the key difference was the introduction of antibiotics that caused a reduction in the child mortality rate
E) infanticide dropped dramatically