What is the primary purpose of cross-examination in court, and how should a PI witness prepare for it?

1. To test the accuracy and credibility of the witness's testimony; by reviewing notes thoroughly and being prepared to answer truthfully and directly.
2. To challenge the opposing counsel's arguments; by developing counter-arguments.
3. To introduce new evidence not previously disclosed; by bringing all raw data.
4. To allow the PI to expand on their findings and theories; by preparing detailed speculative theories.