Correct Answer: (c) Of about forty-five million living species, some 100 are lost every day, most of them unknown, because no more than 1.5 million have been actually identified.
Solution:According to the IUCN, currently, 1.5 to 1.8 million species have been named, but the estimated number of species may be 5 to 10 million. In other estimates, according to the estimates of the highly renowned scientist Irwin, the estimated number of species is about 50 million, and about 30,000 are going extinct every year. Hence, option (c) is the correct answer.