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.

Input: Consider Input: Passage: Beer is composed mostly of water. Regions have water with different mineral components; as a result, different regions were originally better suited to making certain types of beer, thus giving them a regional character. For example, Dublin has hard water well-suited to making stout, such as Guinness; while the Plzeň Region has soft water well-suited to making Pilsner (pale lager), such as Pilsner Urquell. The waters of Burton in England contain gypsum, which benefits making pale ale to such a degree that brewers of pale ales will add gypsum to the local water in a process known as Burtonisation. Question: What type of water is good for making stout beer, like Guinness?

Output: hard water


Input: Consider Input: Passage: Often, through-hole and surface-mount construction must be combined in a single assembly because some required components are available only in surface-mount packages, while others are available only in through-hole packages. Another reason to use both methods is that through-hole mounting can provide needed strength for components likely to endure physical stress, while components that are expected to go untouched will take up less space using surface-mount techniques. For further comparison, see the SMT page. Question: Which type of construction makes components that use more space?

Output: through-hole


Input: Consider Input: Passage: Most historians[who?] consider Caliph Muawiyah (661–80) to have been the second ruler of the Umayyad dynasty, even though he was the first to assert the Umayyads' right to rule on a dynastic principle. It was really the caliphate of Uthman Ibn Affan (644–656), a member of Umayyad clan himself, that witnessed the revival and then the ascendancy of the Umayyad clan to the corridors of power. Uthman placed some of the trusted members of his clan at prominent and strong positions throughout the state. Most notable was the appointment of Marwan ibn al-Hakam, Uthman's first cousin, as his top advisor, which created a stir among the Hashimite companions of Muhammad, as Marwan along with his father Al-Hakam ibn Abi al-'As had been permanently exiled from Medina by Muhammad during his lifetime. Uthman also appointed as governor of Kufa his half-brother, Walid ibn Uqba, who was accused by Hashmites of leading prayer while under the influence of alcohol. Uthman also consolidated Muawiyah's governorship of Syria by granting him control over a larger area and appointed his foster brother Abdullah ibn Saad as the Governor of Egypt. However, since Uthman never named an heir, he cannot be considered the founder of a dynasty. Question: Who was the son of Al-Hakam ibn Abi al-'As?


Output: Marwan ibn al-Hakam