"a dog is man's best friend." that common saying may contain some truth, but dogs are not the only animal friend whose companionship people enjoy. 1 for many people, a cat is their best friend. despite what dog lovers may believe, cats make excellent house pets thanks to their warm companionship, civilized household behavior, and ease of care.
2 in the first place, people enjoy the companionship of cats. many cats are affectionate. they will snuggle up and ask to be petted, or scratched under the chin. 3 who can resist a purring cat? if they're not feeling affectionate, cats are generally quite playful. 4 they love to chase balls and feathers, or just about anything dangling from a string.

identify which underlined sentence links the opinion or reason the writer used to support his or her view point.
a) sentence 1
b) sentence 2
c) sentence 3
eliminate
d) sentence 4