Q: This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
The independence of the ECB is instrumental in maintaining price stability. Not only must the bank not seek influence, but EU institutions and national governments are bound by the treaties to respect the ECB's independence. To offer some accountability, the ECB is bound to publish reports on its activities and has to address its annual report to the European Parliament, the European Commission, the Council of the European Union and the European Council. The European Parliament also gets to question and then issue its opinion on candidates to the executive board.
A:
WHat is the biggest factor in the ECB maintaining price stability?