What about the "human impact" of motorized use of the glen canyon impoundment? we can visualize the floor of the reservoir gradually accumulating not only silt, mud, waterlogged trees and drowned cattle but also the usual debris that is left behind when the urban, industrial style of recreation is carried into the open country. there is also the problem of human wastes. the waters of the wild river were good to drink, but nobody in his senses would drink from lake powell. eventually, as is already sometimes the case at lake mead, the stagnant waters will become too foul even for swimming. the trouble is that while some boats have what are called "self-contained" heads, the majority do not; most sewage is disposed of by simply pumping it into the water. it will take a while, but long before it becomes a solid mass of mud lake powell ("jewel of the colorado") will enjoy a passing fame as the biggest sewage lagoon in the american southwest. most tourists will never be able to afford a boat trip on this reservoir, but everybody within fifty miles will be able to smell it. which rhetorical technique is abbey using in the underlined section of this excerpt? a. ethos b. logos c. ad hominem d. pathos