It probably depends on the Read More link. If it expands the card and displays the whole information, “Submitting a Proposal” without additional navigation to another page is probably a good idea. However, if you click Read More and it takes you to a new page, it might be a bit confusing.
Having a CTA on a card isn’t bad, in fact it’s recommended because every action is different (you’ll be submitting a proposal for a different job each time). On the other hand, if you can’t show the full requirements, you might need to have the CTA on the landing page. In general, for a job board, I think you probably need to use this approach. For example, take a look at Upwork’s approach
if I click on the “more” link, the info expands
you will see, however, that you cannot submit a suggestion. To do that, you have to click on the title of the post, and then an overlay opens that visually looks like a page drawer (it’s not, it just looks like it).
Now, Upwork is not exactly a paradigm in UX. In fact, they’re known for their UX disasters. But it is one of the biggest job boards, and in this particular case, the user flow makes sense.
Let’s take another industry reference: Freelancer.com
You can’t expand the information. If you hover over the job posting, you will see a “Bid Now!” button
However, if you click on it, you will not be able to place a bid or submit a proposal. You will be redirected to a new page, just like on Upwork
There’s nothing wrong with your approaches, but if you research your competitors, you’ll find that none of them allow direct submission.
The options I see are:
- Your A option
- Your B option (removing the “read more “ link, going to a new page).
- Your B2 option with expand info, submitting in same page
- A B3 option (CTA with different wording, just like Luke Sawczak says in his very good answer)
Once you’ve decided on one or more of the above options, you should research this with real users (well, you definitely should) and design the interface based on those results.