<p>D is like the grade D (A/B/C/D/F…)</p>
<p>If you have conventional grades then you can use that class towards your credits, GPA, and major. If it’s pass/D/fail you’re essentially just taking the class for the heck of it. Which can be interesting, and a great idea if you’re taking something you have scant or no experience in. Then if you find out you’re wicked good at it you can switch to the conventional grade system.</p>