MY DAD WAS A FARMER YOU RACIST

Today I'm at work going through all these boxes of files with my co-workers when we come across this file folder full of your average stupid corporate white guy jokey things .... So first this African woman i work with finds and reads this joke, starts chuckling and then passes it to me. Now the joke is right in front of me, and everyone else eagerly stands around me to read it. It should be noted that I am white and everyone else in my office is black. The joke goes like this:

The Farmers Divorce Case:
A farmer walked into his attorney's office wanting to file for divorce.
The attorney asked "May I help you?"
To which the farmer replied "Yea, I want to git one o'those dayvorce thangs."
The lawyer said "Do you have any grounds?"
"Yea" the farmer replied, "I've got 140 acres"
"No, I mean do you have a case*?" responded the lawyer.
"Naw, I ain't got a case, but I got a John Deere" said the farmer. [*Case is a tractor brand you Yuppie jerks]
"No, No, No, you don't understand, I mean do you have agrudge?" asked the lawyer.
"Sure do, that's where I park my John Deere."
The lawyer then said "No sir, I mean do you have a suit."
To which the farmer replied "Yep, I got a suit that I wear to church every Sunday."
The attorney then decided to try a different tack, "Does your wife beat you up or anything?"
"Nope" said the farmer, "we both get up around 4:30."
The attorney then said "Well is she a nagger or something?"
The farmer then perked up and said "Naw, she's a little white gal, but our last child was a nagger and that's why I want the dayvorce."
Ok. At this point does Danny:
a.] Laugh Uncontrollably and then get smacked in the back of the head by a co-worker
b.] Laugh and then pretend that it was a cough/throat clearing, and excuse himself to the bathroom
c.] Furrow his brow and act as if he doesn't understand
d.] Slowly sink into his chair holding his breath until all the surrounding co-workers burst into laughter allowing for the politically-correct-careful smile.

If you guessed d. then your are correct. Which makes me think that maybe I should have been offended at the joke making fun of white people.