4. which of the following is the best example of
biodiversity?
a in sri lanka, over 30 species of tree frog are in
danger of becoming extinct.
b atlantic salmon may swim 500 miles against a
river current just to spawn.
c sequoia national park has more than 1200
plant species.
d birds have feathers with different colors.

C.

Explanation:

Biodiversity refers to the number of unique organisms within a region. C best explains that with the 1200 species of plant.

P.S. Thanks for separating the options. It´s a small detail that helps my eyes.

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.