Chapter 3 $GraphLookup MaxDepth field

I took the quiz and I believe the answer is wrong. The quiz lists the answer as:

depthField determines a field, which contains value of the number of documents matched by the recursive lookup

However I believe the video states that it is the number of recursive lookups needed to match the document.

Also… I my be wrong, but I also don’t believe it states that the value for max depth has to be of type long but I may be wrong.