Mckinsey Junior Research Analyst vs P&G Financial Analyst

Hello to all!

I'm a first year financial analyst at P&G. Recently I interviewed with Mckinsey and got an offer for junior research analyst role.
My ultimate goal is to become a consultant, and would consider to do MBA if that's what it takes to break into MBB. Also, my interest in not finance, and would like to have a project-based job. However, it looks like this JRA role in Mckinsey is back office job and not really related to consulting. If I want to become consultant eventually in MBB, which of the below paths would be more doable?

1. Stay in P&G and do MBA maybe two years after, then join as associate.
2. Take the JRA offer in Mck directly and try to get promotion to BA. If not able to convert to BA then do MBA instead.

Many Thanks!