In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.

Passage: Ratanakiri has been occupied since at least the Stone or Bronze Age, and trade between the region's highlanders and towns along the Gulf of Thailand dates to at least the 4th century A.D. The region was invaded by Annamites, the Cham, the Khmer, and the Thai during its early history, but no empire ever brought the area under centralized control. From the 13th century or earlier until the 19th century, highland villages were often raided by Khmer, Lao, and Thai slave traders. The region was conquered by local Laotian rulers in the 18th century and then by the Thai in the 19th century. The area was incorporated into French Indochina in 1893, and colonial rule replaced slave trading.  The French built huge rubber plantations, especially in Labansiek (present-day Banlung); indigenous workers were used for construction and rubber harvesting. While under French control, the land comprising present-day Ratanakiri was transferred from Siam (Thailand) to Laos and then to Cambodia. Although highland groups initially resisted their colonial rulers, by the end of the colonial era in 1953 they had been subdued.Ratanakiri Province was created in 1959 from land that had been the eastern area of Stung Treng Province. The name Ratanakiri (រតនគិរី) is formed from the Khmer words រតនៈ (ratana "gem" from Sanskrit ratna) and គិរី (kiri "mountain" from Sanskrit giri), describing two features for which the province is known. During the 1950s and 1960s, Norodom Sihanouk instituted a development and Khmerization campaign in northeast Cambodia that was designed to bring villages under government control, limit the influence of insurgents in the area, and "modernize" indigenous communities. Some Khmer Loeu were forcibly moved to the lowlands to be educated in Khmer language and culture, ethnic Khmer from elsewhere in Cambodia were moved into the province, and roads and large rubber plantations were built. After facing harsh working conditions and sometimes involuntary labor on the plantations, many Khmer Loeu left their traditional homes and moved farther from provincial towns. In 1968, tensions led to an uprising by the Brao in which several Khmer were killed. The government responded harshly, torching settlements and killing hundreds of villagers.
What is the former name of the area where the French built huge rubber plantations?