The ability for a person to testify about what they heard in an audio recording when the recording is available revolves around several legal principles, including hearsay and the best evidence rule. In this scenario, option C, which states that a person can testify if they observed the speaker making the statements, is correct. This is grounded in the fact that a witness can provide personal observations and experiences, allowing them to recount what they heard directly from the speaker rather than relying solely on the recording itself.
When a witness actually observes the speaker and hears their statements, their testimony is based on firsthand knowledge, which is permissible in court, independent of the recording. This type of testimony does not disregard the audio recording; rather, it supplements it by providing context or additional detail about the circumstances surrounding the statements.
Conversely, other options hinge on misunderstandings of the legal principles involved. For instance, while the best evidence rule does require presentation of the original recording when the contents of the recording are in dispute, it does not prohibit a witness from discussing their firsthand experiences related to the audio. Furthermore, hearsay guidelines do not obstruct a witness from speaking about their direct observations of the statements made, allowing such testimony as long as it doesn't rely on the content of the recording