Two travelers engaged in a warm dispute about the color of the Chameleon. One of them affi

rmed it was blue, that he had seen it with his own eyes upon the naked branch of a tree, feeding on the air in a very clear day. The other strongly asserted it was green, and that he had viewed it very closely and minutely upon the broad leaf of a fig tree. Both of them were positive, and the dispute was rising to a quarrel; but a third person luckily coming by, they agreed to refer the question to his decision. "Gentlemen," said the Arbitrator, "You could not have been more lucky in your reference, as I happen to have caught one of them last night; but, indeed, you are both mistaken, for the creature is totally black." "Black, impossible." "Nay," said the Umpire, with great assurance, "the matter may be soon decided, for I immediately enclosed my Chameleon in a little box, and here it is." So saying, he drew it out of his pocket, opened the box, and, lo! It was white as snow.

The best lesson that the reader can derive from this fable is ______ .

A．looks are deceiving

B．never judge a book by its cover

C．truth changes with time

D．every yea has its nay