Definitely an A. As a person that buys very few games, PS Plus only adds good games to my collection, and the games that I do buy are rarely added to PS Plus.
Highlights:
Deus Ex: Mankind Divided
Knack
Grand Kingdom
Bloodborne
Ratchet & Clank
Beyond: Two Souls
Yakuza Kiwami
Bulletstorm
And I bought Digimon Story cyber Sleuth, and Metro Last Light on sale.