Answer:
a. the party who did not call the witness.
Explanation:
Cross-examination refers to the interrogation of a witness that was called by the opposite party. Therefore, this means that the party that did not call the witness is the one that conducts the cross-examination. This is an essential component of the trial, as the outcome can be altered when doubt is cast on a witness. Alternatively, the outcome of the trial can also be ensured if the witness is proven to be credible.