fill select field from button

I have a form with select field (with 3 choices).
I have three buttons: pressing first button I would want that first choice is automatically selected; pressing second button I would want that second choice is automatically selected; etc…
If i write this url in button doesn’t work:
http://www.mysite/?&1tag=1(no)

(form 1, first choice selected…)

What’s wrong?

https://wordpress.org/plugins/si-contact-form/