Which of the following is true regarding extinction?
a. if the rate of speciation in a clade is equal to or less than the rate of extinction, the clade will survive. b. the rate of extinction is steady from clade to clade as are the number of species contained within a clade. c. single events or several causes working together to produce extinction in a short period is referred to as mass extinction. d. extinction that occurs in a relatively short period of time is referred to as background extinction.

C. Single events or several causes working together to produce extinction in a short period is referred to as mass extinction.

Example:
Destruction of forests, mountains, and bodies of water to satisfy human needs result to the imbalance of nature which also give rise to global warming.

Animals and plants have lost their habitats. They lost their means to live. They lost their food sources and they suffer and die because of humans irresponsible acts.

hope I helped!!

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.