Given the general incompetence of governments in general (Europe is no exception) I doubt it is (b).
Reminder that France vacuumed up messages on Enrochat after deploying malware globally, and they have clear text messages from users in any arbitrary country and have not disclosed what they will do with it or what they have.
https://www.vice.com/en/article/3aza95/how-police-took-over-...
The US spies on everyone because they can, and because they have prepared to do basically anything they think might be in their interests; when Germany discovers the US spying on them, what can they really do about it? Whereas if it was the other way, all hell would break loose.
Establishing mere capability is pretty trivial: they have diplomats in the United States who can talk to people.
You don’t think the French would love to have known about AUKUS submarine deal before it was made? It’s detrimental to not attempt to spy. The French were blindsided and I’m sure they don’t want to be blindsided again.
[1] https://www.space.com/arianespace-soyuz-rocket-launches-cso-...