Car Show - Providing photos to exhibitor?

Hi there, I'm doing photography purely as a hobby. I took some pictures for friends here and there, but nothing special. But I'm currently in a situation that I want some input on:

Today, I went to a pretty big classic car show with mostly collectors and classic dealers showing off cars. Lots of pretty cars and also pretty accessible. Most exhibitors opened the hoods and doors so you could take better pictures. Overall very nice experience!

While taking pictures, one of the exhibitors asked me if I post my pictures somewhere. I replied with yes, and he then handed me his business card. It was the owner of a classics car dealer, and he asked me if I would send him the picture I took.

But now I'm in kind of dilemma, because the pictures turned out very good (for my expectations at least), and I'm now questioning what he's going to do with the pictures.
The cars I took the pictures of are all for Sale, and I'm kind of afraid that he'll go on to use the pictures as advertisements or even sell them to the owners (the cars in question are not owned by the dealer, but sold in the owners name).

On one hand I really like the pictures, and I'm definitely going to post them to social media anyway, so like.. What gives? If he wants them, he can probably find them anyway?

On the other hand, if he's going to make a profit off of my hobby? I don't know about that.

I've gone over this with my partner and she thinks I should either
A) not send the pictures
B) Send them, and tell him to give credits to me
C) Put on a watermark and tell him that he can buy the pictures if he wants

I'm kind of thinking of a mix between B and C, but I just lack the experience to tell what's appropriate in this situation.

What do you think?