USC!!! Which is harder to get in to??? School of Gerontology or Keck undergraduate??

I am applying to USC this year. And I am currently struggling with which major.
I know that USC accepts by major. For Gerontology, I am interested in the Human Development & Aging, health science track. And for Keck undergraduate, I am interested in the Health Promotion and Disease Prevention major.
Also, I tried to search for activities for Keck undergraduate, but I can barely find anything. Is Keck good for pre-med?

Thank you!!!