Your answer would be... B. The climate on Earth has changed over time.
The species was a keystone species.
Keystone species are the species that ''hold the ecosystem together''.
They have an important role in the trophic networks (food chains) and often they can even afflict changes in the abiotic part of the ecosystem (change the composition of soil, purify the water, lower the effect of the wind etc)
Therefore, when a keystone species is removed it affects greatly the whole ecosystem.
The Miller-Urey experiment showed that simple molecules could have arisen abiotically. This chemical experiment included conditions similar to those present on the early Earth, and tested the origin of life under those conditions.
Water (H2O), methane (CH4), ammonia (NH3) and hydrogen (H2) were the chemicals used to produce the results of the experiment, the factors needed for simple life to arise. Given similar conditions on other planets, it's possible that life could arise there as well.
the answer to your question is 1 1/8
The answer is b, chloroplast.
