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: Beyoncé's music is generally R&B, but she also incorporates pop, soul and funk into her songs. 4 demonstrated Beyoncé's exploration of 90s-style R&B, as well as further use of soul and hip hop than compared to previous releases. While she almost exclusively releases English songs, Beyoncé recorded several Spanish songs for Irreemplazable (re-recordings of songs from B'Day for a Spanish-language audience), and the re-release of B'Day. To record these, Beyoncé was coached phonetically by American record producer Rudy Perez. Question: What style of music does Beyoncé usually perform?
Example Output: R&B

Example Input: Passage: Michael Lynche was the lowest vote getter at top nine and was given the Judges' Save. The next week Katie Stevens and Andrew Garcia were eliminated. That week, Adam Lambert was invited back to be a mentor, the first Idol alum to do so. Idol Gives Back returned this season on April 21, 2010, and raised $45 million. Question: Who was the first American Idol contestant to return to the show as a mentor?
Example Output: Adam Lambert

Example Input: Passage: Neptune's dark spots are thought to occur in the troposphere at lower altitudes than the brighter cloud features, so they appear as holes in the upper cloud decks. As they are stable features that can persist for several months, they are thought to be vortex structures. Often associated with dark spots are brighter, persistent methane clouds that form around the tropopause layer. The persistence of companion clouds shows that some former dark spots may continue to exist as cyclones even though they are no longer visible as a dark feature. Dark spots may dissipate when they migrate too close to the equator or possibly through some other unknown mechanism. Question: Since Neptune's dark spots persist for several months, what are they thought to be?
Example Output:
vortex structures