Which of these are my best options for LOR?

[Derberd]

Background: applying for master in management at French business schools (programs are in English), graduated from a public US university with a BS in Env Science, GPA pretty low at 2.91. I didn't form any close relationships with professors and I graduated in 2017 so it's been almost 2 years. I'm applying to a recruitment program which asks for two LORs, they prefer both academic. I will probably apply to a couple other schools which may ask for one academic and one professional. 

My best options in my opinion:

Advisor for my major: met with her a couple times per year, we talked a lot about my career aspirations/goals, but she was very aware of my GPA and classes I didn't do well in. However, she's an advisor for science, not at all related to business.

Forest biology class I took spring 2017: small class + we went on field trips so I had quite a bit of contact with the professor. I only received a B although I think I did very well on all the tests. 

Environmental Economics class, summer 2015: was a small class that only lasted 4 weeks or something, maybe 12 guys + one girl (me), which could make me memorable to the professor, although it was a long time ago. I received a B and this was my only/first econ class, I enjoyed it quite a bit.

PT student job I had for last 1.5 years of uni - they'd definitely write me a great letter because I know I was reliable/a good worker. The job was doing set up/overseeing events at the school. However this would be a professional recommendation, and I worry that the people I'm competing with would have more prestigious professional recommendations.

Internship summer '17: spent about 10h/week most of the summer here, naturally  got to know my supervisor very well. HOWEVER - the internship was very science-y and mostly consisted of agricultural work. Not at all related to business, but I'm sure they *could* write me a good LOR.

Current nannying job: the father in the family I work for as a nanny since Sept. 2018 is the VP of a large international French company. I'd feel a bit weird asking him for a letter, and all I do is childcare...but I thought it was worth listing this.

Edited January 27, 2019 by Derberd
add 6th option

[ashpokechu]

I would pick your advisor and your PT job's boss. One can provide them with your academic experience and one can speak about your professionalism.