Which sentence best summarizes a central idea of the text?
A burger discovered that smaller animals tended to live longer because they were able to hide or hibernate.
B Some scientists disagree with burgers analysis about the factors involved in a species overall survival rate.
C when burger studied the lifespan of ancient animals, he found 19 types of mammals lasted 20 million years.
D Burger determined that the survival of a species largely depended on a combination of genetic traits and a stable environment.