The assessment is based on consistent, corroborating evidence from multiple relevant sources. A news article from China Daily (Authority: 0.70), a major news outlet, directly reports that the US Consumer Confidence Index was 89.1 in December and correctly attributes the data to 'the Conference Board'. This claim is independently confirmed by a market news update on an agricultural industry website (Authority: 0.50), which also explicitly states that 'The Conference Board's Dec US consumer confidence index fell... to 89.1'. While some of the provided sources are from the primary authority (The Conference Board), they do not contain the specific data point for December, as they discuss different topics. Crucially, none of the provided sources contradict the statement. The convergence of information from two independent secondary sources, with no conflicting evidence, makes the original statement highly probable.