The United Nations' Convention on International Trade in Endangered Species(CITES) recently reaffirmed a 1989 ban on trading ivory, despite calls from Tanzania and Zambia to lift it. Only 470,000 elephants remain in Africa today - compared to 1.3 million in 1979. While natural habitat loss was a significant factor in dwindling elephant populations, poaching for ivory was the main cause. Since the ban'simplementation, elephant populations have recovered in many African countries, but an estimated 38,000 elephants are still killed annually. CITES permitted one-off sales in 1999 and in 2008, allowing approved countries to dispose of their government stockpiles of ivory. Ivory from these sales was exported to Japan and China, where demand for carved ivory is high. Conservation groups vehemently oppose further one-off sales, because much of the ivory sold is of unknown origin. Furthermore, the sales have fuelled far-Eastern demand for ivory. In central and western African countries, where organized crime rings operate lucrative ivory smuggling operations, poaching remains rife. Those in favors of allowing one-off sales argue that elephants are no longer endangered, and that maintaining the ban will simply inflate the price of illegal ivory, making poaching more tempting. Though the CITES decision is viewed as a victory by conservationists, the African elephant's future relies on governments' commitment to enforcing the ban.

Question: Conservationists question the provenance of the ivory sold at one-off sales.
Options:
A. true, B. false, C. uncertain
Answer: "A"