If its true or false its true
The following words should be capitalized: B) A, D) Sound, and C) Thunder.
When it comes to the names of novels an such, all words (except for prepositions and linking verbs) should be capitalized. For example - The Lord of the Rings, A Sound of Thunder, etc.
PCM: Pulse code modulation. It is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, digital telephony and compact discs. The amplitude of this signal is sampled regularly at uniform intervals.
PAM: Pulse amplitude modulation. It is a form of signal modulation where the message information is encoded in the amplitude of a series of signal pulses.