Category Slugs in CustomPress?

I am attempting to use the following code recommended from Wordpress.org to make customizations on different archive pages. I have tried several things, but think it may be different with the Custom Posts from the Custompress plugin. What would I put in place of 'Category A' to customize these pages?

<?php if (is_category('Category A')) { ?>
<p>This is the text to describe category A</p>
<?php } elseif (is_category('Category B')) { ?>
<p>This is the text to describe category B</p>
<?php } else { ?>
<p>This is some generic text to describe all other category pages,
I could be left blank</p>
<?php } ?>