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.

Q: Passage: Hard rock entered the 1990s as one of the dominant forms of commercial music. The multi-platinum releases of AC/DC's The Razors Edge (1990), Guns N' Roses' Use Your Illusion I and Use Your Illusion II (both in 1991), Ozzy Osbourne's No More Tears (1991), and Van Halen's For Unlawful Carnal Knowledge (1991) showcased this popularity. Additionally, The Black Crowes released their debut album, Shake Your Money Maker (1990), which contained a bluesy classic rock sound and sold five million copies. In 1992, Def Leppard followed up 1987's Hysteria with Adrenalize, which went multi-platinum, spawned four Top 40 singles and held the number one spot on the US album chart for five weeks.

A: In which decade did hard rock see a decline of dominance in commercial music?
****
Q: Passage: Uranium carbides and uranium nitrides are both relatively inert semimetallic compounds that are minimally soluble in acids, react with water, and can ignite in air to form U
3O
8. Carbides of uranium include uranium monocarbide (UC), uranium dicarbide (UC
2), and diuranium tricarbide (U
2C
3). Both UC and UC
2 are formed by adding carbon to molten uranium or by exposing the metal to carbon monoxide at high temperatures. Stable below 1800 °C, U
2C
3 is prepared by subjecting a heated mixture of UC and UC
2 to mechanical stress. Uranium nitrides obtained by direct exposure of the metal to nitrogen include uranium mononitride (UN), uranium dinitride (UN
2), and diuranium trinitride (U
2N
3).

A: Along with uranium monocarbide and uranium dicarbide, what is a unnotable carbide of uranium?
****
Q: Passage: The Macintosh (/ˈmækᵻntɒʃ/ MAK-in-tosh; branded as Mac since 1997) is a series of personal computers (PCs) designed, developed, and marketed by Apple Inc. Steve Jobs introduced the original Macintosh computer on January 24, 1984. This was the first mass-market personal computer featuring an integral graphical user interface and mouse. This first model was later renamed to "Macintosh 128k" for uniqueness amongst a populous family of subsequently updated models which are also based on Apple's same proprietary architecture. Since 1998, Apple has largely phased out the Macintosh name in favor of "Mac", though the product family has been nicknamed "Mac" or "the Mac" since the development of the first model.

A:
When was the Microsoft branded as Mac?
****