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.

Most migrations begin with the birds starting off in a broad front. Often, this front narrows into one or more preferred routes termed flyways. These routes typically follow mountain ranges or coastlines, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as large stretches of open water. The specific routes may be genetically programmed or learned to varying degrees. The routes taken on forward and return migration are often different. A common pattern in North America is clockwise migration, where birds flying North tend to be further West, and flying South tend to shift Eastwards.
How do most migrations begin?

A revised version of the ABC logo was introduced for promotions for the 2013–14 season during the network's upfront presentation on May 14, 2013, and officially introduced on-air on June 17 (although some affiliates implemented the new design prior to then), as part of an overhaul of ABC's identity by design agency LoyalKaspar. The updated logo carries a simpler gloss design than the previous version, and contains lettering more closely resembling Paul Rand's original version of the circle logo. The logo is displayed on-air, online and in print advertising in four variants shading the respective color used with the circle design's native black coloring: a gold version is primarily used on entertainment-oriented outlets (such as ABC.com, WATCH ABC, and by ABC Studios) and the on-screen bug; steel blue and dark grey versions are used primarily by ABC News; a red version is used for ESPN on ABC, while all four variants are used selectively in advertising and by affiliates. A new custom typeface, "ABC Modern" (which was inspired by the logotype), was also created for use in advertising and other promotional materials.
In 2013, ABC's identity was revamped by what design agency?

In 1853 the Russian Empire on behalf of the Slavic Balkan states began to question the very existence of the Ottoman Empire. The result was the Crimean War, 1853–1856, in which the British Empire and the French Empire supported the Ottoman Empire in its struggle against the incursions of the Russian Empire. Eventually, the Ottoman Empire lost control of the Balkan region.

When did the Russian Empire begin to question the existence of the Ottoman Empire?

