The kind of thoughts that keep a person from falling asleep can arise in either half of the brain. Therefore, a person being prevented from sleeping solely by such thoughts would be able to fall asleep by closing the eyes and counting sheep, because this activity fully occupies the left half of the brain with counting and the right half with imagining sheep, thereby excluding the sleep-preventing thoughts.

Which one of the following most closely parallels the reasoning in the argument above?

a) Stucco is a poor insulator but brick and wood are good insulators, so a person who wants to build a house in an area with a cold climate should use brick or wood instead of stucco.
b) Cats can damage furniture with either their claws or their teeth, so such damage can be prevented by providing cats with other objects that they will claw and bite, such as toy mice.
c) This map indicates two roads of equal length each leading to Centerville, so a person who wants to take the shortest route to Centerville could choose either one.
d) These chemicals are harmless by themselves but explosive when mixed together, so in order to be kept in the same laboratory without risk, they should be stored separately.
e) This island has two harbours but one of them is too shallow to permit large ships, so this ship will have to dock in teh other harbour in order to unload its cargo.