The table below shows the fossils found in various layers of an undisturbed rock:
fossils in rock layers
layer (from top) fossil in layer
1 a, c
2 e
3 a, d, f
4 b
5 f, c
6 d, b
which is most likely an index fossil?

Here is a picture  of the net. its 4 squares in a row diagonal and on the third draw one square aove and under

Ithink the answer to that would be b):

Humans have survived and thrived in mexico city by using technology to create greater access to land. when the spanish conquered the aztec capital, tenochtitlan, in the 16th century, they built mexico city by draining the lakes and filling in the lake water to create more arable land for agriculture. this technique of land reclamation has continued to be fundamental to human civilization in mexico city.