Read the excerpt below and answer the question.
About the Rebellion and its results he would express no opinion. When asked whether he was not happier now that Jones was gone, he would say only "Donkeys live a long time. None of you has ever seen a dead donkey," and the others had to be content with this cryptic answer.
Based on the context in which it is used, what does the word cryptic mean in this excerpt from Animal Farm?
a)playfully mocking
b)witty and humorous
c)casually disrespectful
d)obscure and mysterious