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.

Example Input: Passage: In the later Imperial era, the burial and commemorative practises of Christian and non-Christians overlapped. Tombs were shared by Christian and non-Christian family members, and the traditional funeral rites and feast of novemdialis found a part-match in the Christian Constitutio Apostolica. The customary offers of wine and food to the dead continued; St Augustine (following St Ambrose) feared that this invited the "drunken" practices of Parentalia but commended funeral feasts as a Christian opportunity to give alms of food to the poor. Christians attended Parentalia and its accompanying Feralia and Caristia in sufficient numbers for the Council of Tours to forbid them in AD 567. Other funerary and commemorative practices were very different. Traditional Roman practice spurned the corpse as a ritual pollution; inscriptions noted the day of birth and duration of life. The Christian Church fostered the veneration of saintly relics, and inscriptions marked the day of death as a transition to "new life". Question: What did St Augustine believe that funeral feasts gave an opportunity for?
Example Output: alms of food

Example Input: Passage: Avicenna was born c. 980 in Afšana, a village near Bukhara (in present-day Uzbekistan), the capital of the Samanids, a Persian dynasty in Central Asia and Greater Khorasan. His mother, named Setareh, was from Bukhara; his father, Abdullah, was a respected Ismaili scholar from Balkh, an important town of the Samanid Empire, in what is today Balkh Province, Afghanistan, although this is not universally agreed upon. His father worked in the government of Samanid in the village Kharmasain, a Sunni regional power. After five years, his younger brother, Mahmoud, was born. Avicenna first began to learn the Quran and literature in such a way that when he was ten years old he had essentially learned all of them. Question: What present-day country was Avicenna born in?
Example Output: Uzbekistan

Example Input: Passage: The logical format of an audio CD (officially Compact Disc Digital Audio or CD-DA) is described in a document produced in 1980 by the format's joint creators, Sony and Philips. The document is known colloquially as the Red Book CD-DA after the colour of its cover. The format is a two-channel 16-bit PCM encoding at a 44.1 kHz sampling rate per channel. Four-channel sound was to be an allowable option within the Red Book format, but has never been implemented. Monaural audio has no existing standard on a Red Book CD; thus, mono source material is usually presented as two identical channels in a standard Red Book stereo track (i.e., mirrored mono); an MP3 CD, however, can have audio file formats with mono sound. Question: What format has never been implemented on CDs?
Example Output:
Four-channel sound