Answer:
C
Step-by-step explanation:
Evolution is where organisms have developed over time from simple to complex. Therefore we can rule out D because older rock layers should have simple organisms and A because new rock layers should have more complex organisms. The previous organisms will be unlike those of today, therefore the correct answer is C.
We are to select 2 people to sit in first row from 6.
This is a problem of Combinations. We are find permutation of 6 people taken 2 at a time. This can be represented as 6C2.
So, the answer is option B