According to "A Thousand Years of Guessing," one monk who wrote a book of riddles noted that he wrote outside during the day and that he "froze" while writing. Based on this fact, what can be inferred?

ARiddles make people feel cold.

BHe did not know the answers to many of the riddles.

CWriting the riddles down was important to him.

DHe never moved as he wrote down the riddles.