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: Hisham suffered still worse defeats in the east, where his armies attempted to subdue both Tokharistan, with its center at Balkh, and Transoxiana, with its center at Samarkand. Both areas had already been partially conquered, but remained difficult to govern. Once again, a particular difficulty concerned the question of the conversion of non-Arabs, especially the Sogdians of Transoxiana. Following the Umayyad defeat in the "Day of Thirst" in 724, Ashras ibn 'Abd Allah al-Sulami, governor of Khurasan, promised tax relief to those Sogdians who converted to Islam, but went back on his offer when it proved too popular and threatened to reduce tax revenues. Discontent among the Khurasani Arabs rose sharply after the losses suffered in the Battle of the Defile in 731, and in 734, al-Harith ibn Surayj led a revolt that received broad backing from Arabs and natives alike, capturing Balkh but failing to take Merv. After this defeat, al-Harith's movement seems to have been dissolved, but the problem of the rights of non-Arab Muslims would continue to plague the Umayyads.

SOLUTION: Who suffered worse defeats in the west?

PROBLEM: Passage: There has, however, been interest among railroad operators in returning to DC use at higher voltages than previously used. At the same voltage, DC often has less loss than AC, and for this reason high-voltage direct current is already used on some bulk power transmission lines. DC avoids the electromagnetic radiation inherent with AC, and on a railway this also reduces interference with signalling and communications and mitigates hypothetical EMF risks. DC also avoids the power factor problems of AC. Of particular interest to railroading is that DC can supply constant power with a single ungrounded wire. Constant power with AC requires three-phase transmission with at least two ungrounded wires. Another important consideration is that mains-frequency 3-phase AC must be carefully planned to avoid unbalanced phase loads. Parts of the system are supplied from different phases on the assumption that the total loads of the 3 phases will even out. At the phase break points between regions supplied from different phases, long insulated supply breaks are required to avoid them being shorted by rolling stock using more than one pantograph at a time. A few railroads have tried 3-phase but its substantial complexity has made single-phase standard practice despite the interruption in power flow that occurs twice every cycle. An experimental 6 kV DC railway was built in the Soviet Union.

SOLUTION: Railroad operators have shown little interest in returning to what?

PROBLEM: Passage: In the late 1980s, many local Chicago house music artists suddenly found themselves presented with major label deals. House music proved to be a commercially successful genre and a more mainstream pop-based variation grew increasingly popular. Artists and groups such as Madonna, Janet Jackson, Paula Abdul, Aretha Franklin, Bananarama, Diana Ross, Tina Turner, Whitney Houston, Steps, Kylie Minogue, Bjork, and C+C Music Factoryhave all incorporated the genre into some of their work. After enjoying significant success in the early to mid-90s, house music grew even larger during the second wave of progressive house (19992001). The genre has remained popular and fused into other popular subgenres, for example, G-house, Deep House, Tech House and Bass House. As of 2015, house music remains extremely popular in both clubs and in the mainstream pop scene while retaining a foothold on underground scenes across the globe.[citation needed]

SOLUTION:
When was the third wave of progressive house?