If you want to look at the majors with highest percentage getting med school acceptances–then it’s either mathematic/statistics or humanities (philosophy, literature, history, classics, modern languages, religion, art, music).
https://www.aamc.org/download/321496/data/factstablea17.pdf
However, this data may be misleading because the number of math and humanities majors applying to med school is small and those who do apply are a highly motivated and self-selecting group.
You will also note that the vast majority of people who are accepted to med school are some flavor of bio major. This happens simply because more bio majors apply to med school than any other group.
There is no one single answer to your question. It’s a “it depends” situation.
BTW, even if you sure you want medicine as an eventual career, every pre-med needs to have Plan B because not only do most freshmen pre-meds not persist to the point of applying to med school, but 60% of those that do apply don’t get accepted.
You may want to investigate post-college employment opportunities for any potential major before you commit yourself to it.
As everyone else has suggested–pick a major that fits your interests and that you will be able do well in. Don’t pick a major because you think it will impress adcomms because it won’t.