I had an answer all typed out and ... somehow it got lost. There were 2 Joash's one was very good. He ruled for 40 years. His monarchy was Judah. The other one was quite a rotten dude. He ruled for 16 years. Given your question, the short answer is A. But there is something most interesting about him: he is not listed in the lineage from David to Jesus. There were 3 other kings that were not listed either. Joash is not mentioned in Luke 3 either.
He is not given credit for any psalms, nor was a prophet. It is true that he preserved David's lineage, but I somehow do not think that is the nature of your question. If left to my own devices, I would answer that he was righteous and that preserved the line from David to Jesus.
However your question suggests that he typified Christ. I would pick that, but don't be surprised if it is B.
