Answer the questions about the diagram.

the organism appears in the least outcrops.
(a, b,c, d)

organisms are the oldest.
(a & b, b& c, c& d, d& a)

the organism would make the best index fossil.
(a, b,c, d)

D

B & C

A

Explanation:

The organism in option D appears only in the outcrop 4 and is not visible in any of the three outcrops. Thus, this organism can be considered as to be least appearing

Hence, option D is correct

The oldest organisms are found at the lowest layer and hence organism in option B and C can be considered as the oldest as they are found in the second most lower layer of their respective outcrops.

Index fossils are the most abundant one. These fossils are easily traceable and must have faced wide range of evolution. Option A fossil is Ammonite which is the most common index fossil known till date

Hence, option A is correct.

the darker peppered moth species were favored due to the fact that the industrial revolution had made all the nearby trees a darker color instead of white.