Backyard gardeners who want to increase the yields of their potato plants should try growing stinging nettles alongside the plants, since stinging nettles attract insects that kill a wide array of insect pests that damage potato plants. It is true that stinging nettles also attract aphids, and that many species of aphids are harmful to potato plants, but that fact in no way contradicts this recommendation, because __. Which one of the following most logically completes the argument? ['the types of aphids that stinging nettles attract do not damage potato plants', 'most aphid species that are harmful to potato plants cause greater harm to other edible food plants', 'insect pests typically cause less damage to potato plants than other harmful organisms do', 'stinging nettles require little care and thus are easy to cultivate']