Hi Guys, i have a question about how a drawing which is drawn per ASME Y14.5M should be interpreted. Sorry not sure if this is the right place but Im kind of out of option and would really appreciate the help!

In the drawing I have attached I need to know what is the interpretation of the center line and implied 90 degree angle on the A side?

Does it mean the top surface (that line A is covering) and the edge surface (That line C is covering) should make 90 degree angle or the center line and line B should make 90 degree angle on top view only? I think the answer is the latter but wanted to see what you think since I am in QA field. So if the side view is like below as long as center line and line B on A side are making 90 degree angle we are still ok even though top surface and edge surface are not 90degree.

(edge view)

I really appreciate you guy's help!