This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.
Q: Passage: In the United Kingdom, a bill is presented for royal assent after it has passed all the required stages in both the House of Commons and the House of Lords. Under the Parliament Acts 1911 and 1949, the House of Commons may, under certain circumstances, direct that a bill be presented for assent despite lack of passage by the House of Lords. Officially, assent is granted by the sovereign or by Lords Commissioners authorised to act by letters patent. It may be granted in parliament or outside parliament; in the latter case, each house must be separately notified before the bill takes effect. Question: Which Houses in the UK must approve a bill before it is assented?
A:
House of Commons and the House of Lords