TASK DEFINITION: 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.
PROBLEM: Passage: Code points in the range U+D800–U+DBFF (1,024 code points) are known as high-surrogate code points, and code points in the range U+DC00–U+DFFF (1,024 code points) are known as low-surrogate code points. A high-surrogate code point (also known as a leading surrogate) followed by a low-surrogate code point (also known as a trailing surrogate) together form a surrogate pair used in UTF-16 to represent 1,048,576 code points outside BMP. High and low surrogate code points are not valid by themselves. Thus the range of code points that are available for use as characters is U+0000–U+D7FF and U+E000–U+10FFFF (1,112,064 code points). The value of these code points (i.e., excluding surrogates) is sometimes referred to as the character's scalar value.

SOLUTION: What is a low-surrogate followed by a high-surrogate called?

PROBLEM: Passage: The formation of the party was formally announced at Sydney Town Hall on 31 August 1945. It took the name "Liberal" in honour of the old Commonwealth Liberal Party. The new party was dominated by the remains of the old UAP; with few exceptions, the UAP party room became the Liberal party room. The Australian Women's National League, a powerful conservative women's organisation, also merged with the new party. A conservative youth group Menzies had set up, the Young Nationalists, was also merged into the new party. It became the nucleus of the Liberal Party's youth division, the Young Liberals. By September 1945 there were more than 90,000 members, many of whom had not previously been members of any political party.

SOLUTION: Where was the formation of the UAP party officially announced?

PROBLEM: Passage: Many mailbox providers are also access providers, while others are not (e.g., Yahoo! Mail, Outlook.com, Gmail, AOL Mail, Po box). The definition given in RFC 6650 covers email hosting services, as well as the relevant department of companies, universities, organizations, groups, and individuals that manage their mail servers themselves. The task is typically accomplished by implementing Simple Mail Transfer Protocol (SMTP) and possibly providing access to messages through Internet Message Access Protocol (IMAP), the Post Office Protocol, Webmail, or a proprietary protocol.

SOLUTION:
All mailbox providers were also what?