Bootstrap Column Same Height with Button

I have the following HTML Code:

<div class="row align-items-center" style="margin: 0; padding: 0;">
   <div class="col-4" style="background-color: red; margin: 0; padding: 2px;">
      <a href="#"><button style="width: 100%;">Test</button></a>
   </div>
   <div class="col-4" style="background-color: red; margin: 0; padding: 2px;">
      <img style="width: 100%;" src="resources/assets/images/square-test.png">
   </div>
   <div class="col-4" style="background-color: red; margin: 0; padding: 2px;">
      <img style="width: 100%;" src="resources/assets/images/square-test.png">
   <div>
</div>

And currently it shows like this...

What can I do for the button height? To make sure it is always the same height as the other columns their width. For width 100% seemed to work fine.