Custom Field Select Box Pulling Values From Custom Post Type

OK, any thoughts on the easiest way to do this?

I have custom post type ‘A’ with the following posts:
Post A
Post B
Post C
etc.

I have another custom post type ‘B’ and I need a select box with the values:
Post A
Post B
Post C
etc.

How do I dynamically pull the post titles from post type ‘A’ as values for the custom select box in post type ‘B’?

I can handle creating the post types. It is the custom select box that I’m stuck on.

Thanks in advance for any help!