Correct Option (A)
Assumption 1 is valid. The passage explicitly states that the extinction of species is an outcome for those "which cannot overcome environmental adversity." This directly implies that only species possessing the ability to surmount environmental catastrophes will survive and perpetuate.
Incorrect Options:
- Assumption 2 is not valid. The passage mentions that "more than 90% of species that have ever lived on the earth are now extinct." This refers to the historical extinction rate of species throughout Earth's history, not to the current percentage of existing species that are in danger of extinction due to drastic environmental changes.
- Assumption 3 is not valid. The passage compares Darwinian laws to those of Copernicus, Galileo, Newton, and Einstein, describing them as "sets of natural laws that explain natural phenomena in the universe." This comparison establishes their scientific credibility and explanatory power within their respective fields, but it does not claim that Darwin's theory provides an explanation for all natural phenomena universally.