Please help i've been stuck on this for two days now

How many variables are altered in a good experiment? a.1 b.0 c.2 d.3

The accompanying figure shows the percent of selected dna sequences that match between a chimpanzee and other primates. these data support the hypothesis that the figure shows the percentage of selected d n a sequences that match between the chimpanzee and other primates. the human has an almost 98 percent match, the gorilla has an almost 97 percent match, the orangutan has a 96 percent match, the gibbon has an almost 95 percent match, and the old world monkey has an almost 92 percent match. the accompanying figure shows the percent of selected dna sequences that match between a chimpanzee and other primates. these data support the hypothesis that the figure shows the percentage of selected d n a sequences that match between the chimpanzee and other primates. the human has an almost 98 percent match, the gorilla has an almost 97 percent match, the orangutan has a 96 percent match, the gibbon has an almost 95 percent match, and the old world monkey has an almost 92 percent match. chimpanzees and gibbons are the most closely related the chimpanzee's closest surviving relative is humans orangutans are the primates least closely related to chimpanzees old world monkeys and gibbons are the most closely related

Use this dichotomous key for insect identification to identify the insect shown. 1. a. insect has one pair of wings. order diptera b. insect has two pairs of wings. go to #2 2. a. front wings thicker in texture than hind wings go to #3. b. front and hind wings are same texture throughout. go to #4 3. a. front wings are short order dermaptera b. front wings cover entire abdomen order coleoptera 4. a. wings with scale on all parts of their area. order lepidoptera b. wings without scales go to #5. 5. a. hind wings smaller than front wings. order ephemeroptera b. front and hind wings nearly equal in size. order odonata the insect pictured is in the order diptera. ephemeroptera. coleoptera. odonata.