22.请阅读Passage 2,完成第1～5小题。 　　Passage 2 　　The An

[单选题]22.请阅读Passage 2,完成第1～5小题。 　　Passage 2 　　The Ancient Greek philosopher Pythagoras is best known today for his mathematical theorem,which haunts the dreams of many geometry students,but for centuries he was also celebrated as thefather of vegetarianism.A meatless diet was referred to as a“Pythagorean diet”for years,up untilthe modern vegetarian movement began in the mid-1800s. 　　While Pythagoras was an early proponent of a meatless diet,humans have been vegetarianssince well before recorded history.Most anthropologists agree that early humans would have eaten apredominantly plant-based diet;after all,plants can't run away.Additionally,our digestive systemsresemble those of herbivores closer than camivorous animals.Prehistoric man ate meat,of course,but plants formed the basis of his diet. 　　Pythagoras and his many followers practiced vegetarianism for several reasons,mainly dueto religious and ethical objections.Pythagoras believed all living beings had souls.Animals wereno exception,so meat and fish were banished from his table.Strangely enough,he also banished avegetable that has a place of honor on most vegetarian menus today,the“humble”bean.His followerswere forbidden to eat or even touch beans,because he thought beans and humans were created fromthe same material.Fava beans were especially bad,as they have hollow steams that could allow thesouls ofthe dead to travel up from the soil into the growing beans. 　　While the edict against beans was lifted not long after Pythagoras' death,his followers continued to eat a meatless diet.His principles infiuenced generations of academics and religiousthinkers,and it was a group of these like-minded individuals who founded the Vegetarian Societyin English in the mid-1800s.The virtues of temperance,abstinence and self-control were all tied tovegetarian ideals,while lust,drunkenness and general hooliganism all resulted from a diet too richin meat products.Notable early vegetarians included Leo Tolstoy,George Bernard Shaw,MahatmaGandhi and American Bronson Alcott,a Transcendentalist teacher,reformer and the father oflittleWomen author Louisa May Alcott. 　　It wasn't until the 1960s that vegetarianism moved into mainstream American life and themovement's growth picked up speed in the 1970s when a young graduate student named FrancisMoore Lappe wrote a book called Diet for a Small Planet.In it,she advocated a meatless diet not for ethical or moral reasons,but because plant-based foods have much less impact on the environmentthan meat does.Today,many vegetarians refuse meat because of animal rights issues,or concernsover animal treatment,a principle first espoused in Peter Singer's 1975 work Animal Liberation.

What issue were vegetarians in the mid-1800s in England primary reason with whenrefusing to eat meat?

A. Environmental protection.
B. Animal rights.
C. Religious belief.
D. Moral purity.