Final answer:
Attenuation increases with increasing path length, absorption, frequency, and acoustic impedance. Therefore, for a wave, the correct answer is e) all of the above. These factors collectively contribute to the weakening of a wave as it propagates.
Step-by-step explanation:
The question pertains to the factors that influence attenuation of a wave, which is a general term used to describe any reduction in the strength of a signal or its amplitude. Attenuation increases with increasing: (a) path length; as a wave traverses more distance, it is more likely to encounter material and relaxational losses that diminish its energy. It also increases with increasing (b) absorption; a wave that is absorbed by the medium through which it is traveling will have its energy reduced more swiftly. When it comes to (c) frequency, higher frequencies often result in greater attenuation because they tend to be absorbed more easily by most media. Finally, an increase in (d) acoustic impedance, which is the resistance a material imposes to the passage of sound waves, can also cause increased attenuation, as it reflects and absorbs more sound energy. Therefore, the correct answer is (e) all of the above.