Why is the answer - d? Where is the evidence that it has been challenged later? Only postulates is written.
What is wrong with a and b?
Why is the answer - d? Where is the evidence that it has been challenged later? Only postulates is written.
What is wrong with a and b?
a - M dude is not taking about longevity
b - animals not equal species (from what biology I remember), also, longevity is mentioned(long-lived) just before the highlighted sentence .
Also, challenged can mean : to take exception to