Please Explain

@smilde11 sure! First, let's diagram the stimulus: "If a spoken language is completely efficient, then every possible permutation of its basic language sounds can be an understandable word." CE ==> EPPUW not EPPUW ==> not CE "However, if the human auditory system is an imperfect receptor of sounds, then it is not true that every possible permutation of a spoken language's basic language sounds can be an understandable word." not PRS ==> not EPPUW EPPUW ==> PRS PRS = perfect receptor of sounds Notice that we can combine these two principles using the transitive property as follows: not PRS ==> not EPPUW ==> not CE And this is exactly what (E) says, i.e. "If the human auditory system is an imperfect receptor of sounds (i.e. not PRS), then a spoken language cannot be completely efficient (i.e. not CE)." not PRS ==> not CE Hope that helps! Please let us know if you have any other questions.