James Jay's invisible ink did not become visible by heating. As he described it, his ink "would elude the generally known means of detection, and yet could be rendered visible by a suitable counterpart." Jay's invisible ink consisted of two chemicals. An agent used one chemical to write an invisible message. To read the message, the reader had to brush a second chemical on the paper; that chemical made the message visible. The two-bottle system, supplied by Jay, gave Washington the secure form of writing that he wanted.

I think it was B

James Jay created an invisible ink system that required two chemicals

Explanation:

An explicit information can be defined as that type of information that is clearly stated, leaving nothing implied. For example, the phrase "it was a dark and stormy night," uses explicit information that leaves no room for debate. The reader cannot assume, by any stretch of the imagination, that the story is in fact taking place on a sunny morning.

Hence, from our read the statement James Jay created an invisible ink system that required two chemicals

includes an explicit information.