The most authoritative and relevant source in the provided list directly supports the claim that international equity ETFs received $51.6 billion in net inflows in January, and that this represented the highest monthly inflow on record. This source offers both quantitative figures and contextual confirmation of the record-setting nature of these inflows. While other sources provide more general commentary on market trends, emerging markets, or individual ETFs, none contradict the claim and their less directly relevant content does not undermine the primary evidence. The ETF Trends article is credible and industry-focused, and the specific numbers and 'record' characterization align exactly with the statement under review. Given the strong match between the key evidence and the claim, the probability that it is true is high, though a small margin for potential error remains due to the absence of multiple independent confirmations in the provided sources.