(B) Habitat loss and fragmentation is the most important cause driving animals and plants to extinction.
The most dramatic examples of habitat loss come from tropical rain forests.
Once covering more than $14$ percent of the earth's land surface,these rain forests now cover no more than $6$ percent.
They are being destroyed fast.
By the time you finish reading this chapter,$1000$ more hectares of rain forest would have been lost.
The Amazon rain forest (it is so huge that it is called the 'lungs of the planet') harbouring probably millions of species is being cut and cleared for cultivating soybeans or for conversion to grasslands for raising beef cattle.