Answer:
A mildly sarcastic
Step-by-step explanation:
The letter that the College of William and Mary received had a mildly sarcastic tone because although it says they are "thankful", then they describe everything that their young men who went to the College couldn't do and how "they were totally good for nothing". And also specially because of how it ends: "We are, however, not the less oblig’d by your kind Offer, tho’ we decline accepting it; and, to show our grateful Sense of it, if the Gentlemen of Virginia will send us a Dozen of their Sons, we will take care of their Education; instruct them in all we know, and make Men of them."