Final answer:
The corresponding (senior) author of a scientific journal is usually listed last, indicating they had significant involvement in the research or supervision of the project.Thus the correct answer is 2.
Step-by-step explanation:
The corresponding (senior) author of a scientific journal is usually listed last. This convention can vary somewhat between different fields and journals, but generally, the last position denotes the person who has made the most significant contribution to the research or who has provided overall supervision and research direction. The first author typically is the individual who did the most work on the paper, such as conducting experiments and writing, while the senior author, listed last, is often the leader of the research team.