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

Passage: Another milestone in the early development of Baptist doctrine was in 1638 with John Spilsbury, a Calvinistic minister who helped to promote the strict practice of believer's baptism by immersion. According to Tom Nettles, professor of historical theology at Southern Baptist Theological Seminary, "Spilsbury's cogent arguments for a gathered, disciplined congregation of believers baptized by immersion as constituting the New Testament church gave expression to and built on insights that had emerged within separatism, advanced in the life of John Smyth and the suffering congregation of Thomas Helwys, and matured in Particular Baptists."
When did John Spilsbury create the strict practice of immersion?

Passage: Burdened with debt, in 2004 Vivendi Universal sold 80% of Vivendi Universal Entertainment (including the studio and theme parks) to General Electric, parent of NBC. The resulting media super-conglomerate was renamed NBCUniversal, while Universal Studios Inc. remained the name of the production subsidiary. After that deal, GE owned 80% of NBC Universal; Vivendi held the remaining 20%, with an option to sell its share in 2006. GE purchased Vivendi's share in NBCU in 2011 and in turn sold 51% of the company to cable provider Comcast. Comcast merged the former GE subsidiary with its own cable-television programming assets, creating the current NBCUniversal. Following Federal Communications Commission (FCC) approval, the Comcast-GE deal was closed on Jan 29, 2011. In March 2013, Comcast bought the remaining 49% of NBCUniversal for $16.7 billion.

What percentage did General Electric sell to Vivendi Universal?