What does the comment 'This is logical.' in line 5 of the first paragraph (underlined) mean?
A.
There is no clear way to determine the extent of our ancestor's knowledge of plants.
B.
It is not surprising that early humans had a detailed knowledge of plants.
C.
It is reasonable to assume that our ancestors behaved very much like people in preindustrial societies.
D.
Human knowledge of plants is well organized and very detailed.