请教FF135 Q60

60. One of the more reliable
methods of determining regional climatic conditions in prehistoric periods is
to examine plant pollen trapped in glacial ice during ancient times. By
comparing such pollen samples with spores take from modern vegetation,
scientists can figure out approximately what the weather was like at the time
of pollen deposition. Furthermore, by submitting the prehistoric samples to
radiocarbon dating techniques, we can also determine when certain climatic
conditions were prevalent in that portion of the globe.

Which one of the following may be
inferred from the information in the passage?

A.       
The earth has undergone several glacial periods.

B.       
Radiocarbon dating can be corroborated by
glacial evidence.

C.       
Similarities between prehistoric and
contemporary climates do not exist.

D.       Pollen
deposition is a fairly continuous process.

E.       
Certain flora are reliably associated with
particular climatic conditions.