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 predominant school of thought in the 13th century was the Thomistic reconciliation of the teachings of Aristotle with Christian theology. The Condemnation of 1277, enacted at the University of Paris, placed restrictions on ideas that could be interpreted as heretical; restrictions that had implication for Aristotelian thought. An alternative was presented by William of Ockham, who insisted that the world of reason and the world of faith had to be kept apart. Ockham introduced the principle of parsimony – or Occam's razor – whereby a simple theory is preferred to a more complex one, and speculation on unobservable phenomena is avoided.
Which philosophy attempted to reconcile Aristotelian teachings and Christian theology in the 12th century?

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.
Railroad operators have shown little interest in returning to what?

Passage: In 2002, the Taiwan Solidarity Union, a party with about 10% of the Legislative Yuan seats at the time, suggested making Taiwanese a second official language. This proposal encountered strong opposition not only from Mainlander groups but also from Hakka and Taiwanese aboriginal groups who felt that it would slight their home languages, as well as others including Hoklo who objected to the proposal on logistical grounds and on the grounds that it would increase ethnic tensions. Because of these objections, support for this measure was lukewarm among moderate Taiwan independence supporters, and the proposal did not pass.

What did Mainlander groups suggest in 2002?