I got one D. I still had 3.5 GPA in spite of that,and no one said anything to me about it. The course was a core course, and the undergrad advisor cursed me for a moment before he realised that the bitch gave D to some others too, one of them was american superstar of the department.

When I applied for grad school, I still made into a good school. I had to scrounge for a great excuse, however, while writing for application paper.