How to pre-populate a dropdown form

I have a landing page on my website with a form and am curious if it's possible to pre-populate the dropdown on the form based on where the user is coming from.

We have a representative program where, if they include a link to our landing page on their website and a user clicks on it, the user is taken to our landing page. There is a dropdown on the form called "Choose your representative company from the list" and the user would choose which representative company's website they came from. Is there any way to automatically pre-populate the representative company in the dropdown based on the website the user came from?