This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Ex Input:
Passage: Subsequently, in October 2001, U.S. forces (with UK and coalition allies) invaded Afghanistan to oust the Taliban regime. On 7 October 2001, the official invasion began with British and U.S. forces conducting airstrike campaigns over enemy targets. Kabul, the capital city of Afghanistan, fell by mid-November. The remaining al-Qaeda and Taliban remnants fell back to the rugged mountains of eastern Afghanistan, mainly Tora Bora. In December, Coalition forces (the U.S. and its allies) fought within that region. It is believed that Osama bin Laden escaped into Pakistan during the battle.

Ex Output:
What city fell by mid-October in the invasion of Afghanistan? 


Ex Input:
Passage: Many sensor systems rely on light as the signal source. LEDs are often ideal as a light source due to the requirements of the sensors. LEDs are used as motion sensors, for example in optical computer mice. The Nintendo Wii's sensor bar uses infrared LEDs. Pulse oximeters use them for measuring oxygen saturation. Some flatbed scanners use arrays of RGB LEDs rather than the typical cold-cathode fluorescent lamp as the light source. Having independent control of three illuminated colors allows the scanner to calibrate itself for more accurate color balance, and there is no need for warm-up. Further, its sensors only need be monochromatic, since at any one time the page being scanned is only lit by one color of light. Since LEDs can also be used as photodiodes, they can be used for both photo emission and detection. This could be used, for example, in a touchscreen that registers reflected light from a finger or stylus. Many materials and biological systems are sensitive to, or dependent on, light. Grow lights use LEDs to increase photosynthesis in plants, and bacteria and viruses can be removed from water and other substances using UV LEDs for sterilization.

Ex Output:
What video game console doesn't use infrared LEDs?


Ex Input:
Passage: Ann Arbor's residential neighborhoods contain architectural styles ranging from classic 19th-century and early-20th-century designs to ranch-style houses. Among these homes are a number of kit houses built in the early 20th century. Contemporary-style houses are farther from the downtown district. Surrounding the University of Michigan campus are houses and apartment complexes occupied primarily by student renters. Tower Plaza, a 26-story condominium building located between the University of Michigan campus and downtown, is the tallest building in Ann Arbor. The 19th-century buildings and streetscape of the Old West Side neighborhood have been preserved virtually intact; in 1972, the district was listed on the National Register of Historic Places, and it is further protected by city ordinances and a nonprofit preservation group.

Ex Output:

What 62-story condominium is the tallest building in Ann Arbor?