Resume title

Good morning!

I have a somewhat random question for you today: it's the silliness of HR job titles. I have three titles at my job:

1) What HR says is my job based off of my "band" (aka promotion level)
2) What my business card says
3) What I actually do

1) So technically my title is "Senior Product Consultant". The "senior" part is me being promoted in January of this year. HR only has a set number of titles any position in marketing can have, and our product managers at my band level all have the same title, even though our roles couldn't be more different. Silly, yes?

2) My business card says "Marketing Consultant". Again, I am in no way a consultant, but due to our internal structure I can't use certain more established terms to describe my job. My job is actually a brand new role in a brand new organization ". .. ... ... OEM BD" if you like corporate acronyms. The "BD" part of our structure actually stands for business development, which is more of what I do.

3) My role is really a mix of business development and commercial marketing. I do some marketing research, but I mostly create and execute go to market plans for emerging OEM industries for my business. I am only tied to a certain family of products, and I've done a great job penetrating these markets through thought leadership activities, poster sessions, speaking at conferences, etc. I'm more solution/executive messaging oriented rather than product-focused. Most of my efforts are on trade shows, hospitality events, and creating leads for our sales teams. I own the relationship in most of the opportunities and see them through but sometimes "hand them off" to sales where appropriate. I help influence these OEMs to drive specifications for my company's products.

I initially put "Senior Business Developer, Emerging Vertical OEM Markets" on my resume to reflect 1) I got promoted in my business developer role this January with expanded roles/responsibilities and 2) to reflect what industries I support, being emerging vertical OEM markets (fuel cell, battery, solar, etc.). I am only 25 with four years of work experience, so I want to be careful not to sound too "puffed up" if that's the case.

These b schools will conduct background checks, and my company is very un-supportive of recommendations (not even allowed on LinkedIn). I don't want to cause alarm if my actual title (and very hilariously incorrect, since I don't consult on products) doesn't reflect what I put on my resume. Should I go with option 1, 2, or 3? With Harvard I went with option 1 to be safe but am unsure if that was the best move. Do AdComs know this or is this silliness my gigantic firm? It feels like a global box of about 30 non-senior positions that they force all 400,000+ employees to fit in.

Thanks in advance!