I think this paper was on par with June 2015. On that basis, I'm going to say 62-63 for an A.
The knowledge tested was typical C1 content. I think the hardest question, conceptually, was the one that used the discriminant (8a if I remember correctly). However, a similar question was tested previously on the Jan 16 international (IAL) paper. The area question required some abstract thinking about the properties of the graph.
Well done if you got those questions all correct.