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.

Passage: Conventional ("tailhook") aircraft rely upon a landing signal officer (LSO, radio call sign paddles) to monitor the aircraft's approach, visually gauge glideslope, attitude, and airspeed, and transmit that data to the pilot. Before the angled deck emerged in the 1950s, LSOs used colored paddles to signal corrections to the pilot (hence the nickname). From the late 1950s onward, visual landing aids such as Optical Landing System have provided information on proper glide slope, but LSOs still transmit voice calls to approaching pilots by radio.
What does OSL stand for?

Passage: Between 1925 and 1940, philanthropic foundations, especially ones connected with the Rockefellers, contributed about $7 million to support the Yale Institute of Human Relations and the affiliated Yerkes Laboratories of Primate Biology. The money went toward behavioral science research, which was supported by foundation officers who aimed to "improve mankind" under an informal, loosely defined human engineering effort. The behavioral scientists at Yale, led by President James R. Angell and psychobiologist Robert M. Yerkes, tapped into foundation largesse by crafting research programs aimed to investigate, then suggest, ways to control, sexual and social behavior. For example, Yerkes analyzed chimpanzee sexual behavior in hopes of illuminating the evolutionary underpinnings of human development and providing information that could ameliorate dysfunction. Ultimately, the behavioral-science results disappointed foundation officers, who shifted their human-engineering funds toward biological sciences.
How much did philanthropic foundations donate between 1935 and 1940?

Passage: In addition, like most Slavic languages, the Shtokavian verb also has one of two aspects: perfective or imperfective. Most verbs come in pairs, with the perfective verb being created out of the imperfective by adding a prefix or making a stem change. The imperfective aspect typically indicates that the action is unfinished, in progress, or repetitive; while the perfective aspect typically denotes that the action was completed, instantaneous, or of limited duration. Some Štokavian tenses (namely, aorist and imperfect) favor a particular aspect (but they are rarer or absent in Čakavian and Kajkavian). Actually, aspects "compensate" for the relative lack of tenses, because aspect of the verb determines whether the act is completed or in progress in the referred time.

What are two aspects the Kajkavian verb has?