What can scientists determine by examining 1,000 year-old pollen trapped in the ground?

A. The amount of plants still alive with the same type of pollen.

B. What caused you the death of the plants and animals in an area.

C. The approximate time a specific plant went extinct.

D. What plants once lived in an area.

All these options are correct.

Explanation:

Palynology is the study of the record formed by living and fossilized pollen grains and spores. Paleontologists use this technique to understand different evolutionary and geographical processes as described in the options of this question. Since the pollen grains and the spores are geographically specific and sensitive to the climate, this technique is used in order to reconstruct past vegetation and to describe past climatic conditions, being also useful to describe evolutionary events such as extinction and radiation processes.

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.