This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

[EX Q]: The Thuringian Realm existed until 531 and later, the Landgraviate of Thuringia was the largest state in the region, persisting between 1131 and 1247. Afterwards there was no state named Thuringia, nevertheless the term commonly described the region between the Harz mountains in the north, the Weiße Elster river in the east, the Franconian Forest in the south and the Werra river in the west. After the Treaty of Leipzig, Thuringia had its own dynasty again, the Ernestine Wettins. Their various lands formed the Free State of Thuringia, founded in 1920, together with some other small principalities. The Prussian territories around Erfurt, Mühlhausen and Nordhausen joined Thuringia in 1945.
[EX A]: How long did the Thuringian realm exist?

[EX Q]: After World War II, two new competing formats came onto the market and gradually replaced the standard "78": the 33 1⁄3 rpm (often just referred to as the 33 rpm), and the 45 rpm (see above). The 33 1⁄3 rpm LP (for "long-play") format was developed by Columbia Records and marketed in June 1948. RCA Victor developed the 45 rpm format and marketed it in March 1949, each pursuing their own r&d in secret. Both types of new disc used narrower grooves, intended to be played with smaller stylus—typically 0.001 inches (25 µm) wide, compared to 0.003 inches (76 µm) for a 78—so the new records were sometimes called Microgroove. In the mid-1950s all record companies agreed to a common recording standard called RIAA equalization. Prior to the establishment of the standard each company used its own preferred standard, requiring discriminating listeners to use pre-amplifiers with multiple selectable equalization curves.
[EX A]: What two formats replaced the 78?

[EX Q]: This method involves coating LEDs of one color (mostly blue LEDs made of InGaN) with phosphors of different colors to form white light; the resultant LEDs are called phosphor-based or phosphor-converted white LEDs (pcLEDs). A fraction of the blue light undergoes the Stokes shift being transformed from shorter wavelengths to longer. Depending on the color of the original LED, phosphors of different colors can be employed. If several phosphor layers of distinct colors are applied, the emitted spectrum is broadened, effectively raising the color rendering index (CRI) value of a given LED.
[EX A]:
What method involves coating LEDs of one color with phosphors of different colors?