Regarding the processing and preservation of research data, which of the following statements is correct? (1)To protect subjects' privacy, researcher should destroy all research data, specimens, and samples once the research is complete. (2)Researchers should handle all research matters with care and caution. In principle, the retention period of research data is 300 years post-publication. (3)Researchers should record all experimental data and confirm the correctness of the data during the research process. (4)When the statistical analysis results do not meet the expectations, a statistical expert can be asked to adjust the data in line with the expectations