Starting on June 15th 2017, when roaming withing the EEA (all EU countries, Iceland, Lichtenstein and Norway), you will not be charged more than the price for a domestic call on your home network if you call any fixed or mobile number within the EEA. If you have a subscription plan with included minutes, these minutes will also be valid when roaming. You can not be charged for receiving calls.
So, the answer to your question is A.
One point where the regulation seems unclear is how to charge calls to service lines using so called shared cost services (like area codes 0845 in UK or 0180 in Germany). For example my cell phone subscription includes all calls to regular fixed line or mobile phone numbers, but has a relatively steep charge per minute for calls to shared cost numbers. There are even different charges depending on the type of shared cost service. If I roam in another EEA country and call a shared cost service in that country or another EEA country, it is not obvious from the wording in the regulation if the call should be covered by my included minutes, or if my operator can charge for it and at which rate.
International calls from your home network to other EEA countries are not covered by the regulation and can be charged as your provider likes.