I don't think C is Viburnum opulus. (Had one in my old garden.)
I've had another look at Physocarpus on the internet and I can see now that the foliage is similar to my plant. (For some reason, when I first checked online, it came up with Gomphocarpus physocarpus, which looks completely different! Hence my surprise at Trethew's suggestion.)
Now to wait for the flowers and then I can check the answers are all right! Thank you all for your help!