Explanation

For local regulatory reporting purposes, subsidiaries typically prepare financial statements in the local currency of the country where they are incorporated and regulated.

In this case:

• The subsidiary is located in the UK
• UK regulators require financial statements to be presented in GBP (British Pound)
• While the subsidiary's primary activities are in Europe, the regulatory reporting requirement is based on the jurisdiction where the subsidiary is incorporated
• EUR might be the functional currency if the primary economic environment is in Europe, but for local regulatory reporting, GBP would be required
• USD is the parent company's currency, which is not relevant for local regulatory reporting

Therefore, the financial statements for local regulators are most likely presented in GBP.