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: The oak forests of the southern and central Appalachians consist largely of black, northern red, white, chestnut and scarlet oaks (Quercus velutina, Q. rubra, Q. alba, Q. prinus and Q. coccinea) and hickories, such as the pignut (Carya glabra) in particular. The richest forests, which grade into mesic types, usually in coves and on gentle slopes, have dominantly white and northern red oaks, while the driest sites are dominated by chestnut oak, or sometimes by scarlet or northern red oaks. In the northern Appalachians the oaks, except for white and northern red, drop out, while the latter extends farthest north.
What is the dominate type of oak in the Appalachians?

Passage: He worked in street construction for a short amount of time, but was unable to cope with the heavy labour. Continuing to attend university as a guest student, he started an apprenticeship as cabinetmaker, which he completed as a journeyman. He was dreaming at that time of starting a daycare facility for children, for which he assumed the ability to make furniture might be useful. After that he did voluntary service in one of psychoanalyst Alfred Adler's clinics for children. In 1922, he did his matura by way of a second chance education and finally joined the University as an ordinary student. He completed his examination as an elementary teacher in 1924 and started working at an after-school care club for socially endangered children. In 1925, he went to the newly founded Pädagogisches Institut and continued studying philosophy and psychology. Around that time he started courting Josefine Anna Henninger, who later became his wife.
What was easy for Popper to cope with?

Passage: The history of the area that now constitutes Himachal Pradesh dates back to the time when the Indus valley civilisation flourished between 2250 and 1750 BCE. Tribes such as the Koilis, Halis, Dagis, Dhaugris, Dasa, Khasas, Kinnars, and Kirats inhabited the region from the prehistoric era. During the Vedic period, several small republics known as "Janapada" existed which were later conquered by the Gupta Empire. After a brief period of supremacy by King Harshavardhana, the region was once again divided into several local powers headed by chieftains, including some Rajput principalities. These kingdoms enjoyed a large degree of independence and were invaded by Delhi Sultanate a number of times. Mahmud Ghaznavi conquered Kangra at the beginning of the 10th century. Timur and Sikander Lodi also marched through the lower hills of the state and captured a number of forts and fought many battles. Several hill states acknowledged Mughal suzerainty and paid regular tribute to the Mughals.

During what period did Dagis exist, and then become conquered by the Gupta Empire?