In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Input: Consider Input: What do you need in addition to the LaserDisc in order to experience surround sound?, Context: Only one 5.1 surround sound option exists on a given LaserDisc (either Dolby Digital or DTS), so if surround sound is desired, the disc must be matched to the capabilities of the playback equipment (LD Player and Receiver/Decoder) by the purchaser. A fully capable LaserDisc playback system includes a newer LaserDisc player that is capable of playing digital tracks, has a digital optical output for digital PCM and DTS audio, is aware of AC-3 audio tracks, and has an AC-3 coaxial output; an external or internal AC-3 RF demodulator and AC-3 decoder; and a DTS decoder. Many 1990s A/V receivers combine the AC-3 decoder and DTS decoder logic, but an integrated AC-3 demodulator is rare both in LaserDisc players and in later A/V receivers.

Output: playback equipment


Input: Consider Input: What was the enrollment rate for girls in 1998, Context: Education is compulsory from the age of 7 to 13. The enrollment of boys is higher than that of girls. In 1998, the gross primary enrollment rate was 53.5%, with higher enrollment ratio for males (67.7%) compared to females (40%).

Output: 40%


Input: Consider Input: What are the things that are necessary for this process to function?, Context: The development of quadraphonic records was announced in 1971. These recorded four separate sound signals. This was achieved on the two stereo channels by electronic matrixing, where the additional channels were combined into the main signal. When the records were played, phase-detection circuits in the amplifiers were able to decode the signals into four separate channels. There were two main systems of matrixed quadraphonic records produced, confusingly named SQ (by CBS) and QS (by Sansui). They proved commercially unsuccessful, but were an important precursor to later surround-sound systems, as seen in SACD and home cinema today.
Output: phase-detection circuits in the amplifiers