The best objective summary of the excerpt is: Steve and the narrator tried to strand Spot on an island to relieve themselves of the troublesome dog, and after losing two other good dogs in the process, they felt a sense of relief and happiness at finally being free from the burden of Spot.
However, since the given responses do not directly match my summary, the closest option is: Steve and the narrator tried to strand Spot on an island, but somehow he found them again, even in a large settlement. (Note: This response does not completely align with the excerpt, as it implies Spot returned, which is not indicated in the chosen passage.)