Make an image responsive - the simplest way
Width: 100% will break it when you view on a wider are.
Following is Bootstrap's img-fluid
.
max-width: 100%;
display: block;
height: auto;
You can try doing
<p>
<a href="MY WEBSITE LINK" target="_blank">
<img src="IMAGE LINK" style='width:100%;' border="0" alt="Null">
</a>
</p>
This should scale your image if in a fluid layout.
For responsive (meaning your layout reacts to the size of the window) you can add a class to the image and use @media
queries in CSS to change the width of the image.
Note that changing the height of the image will mess with the ratio.