The feature of continuous auditing that provides the BEST level of assurance over traditional sampling is that voluminous data can be analyzed at a high speed to show relevant patterns. This is because continuous auditing is a technique that uses automated tools and processes to perform audit activities on a continuous or near-real-time basis, and to analyze large amounts of data from various sources and systems. Continuous auditing helps to provide a higher level of assurance than traditional sampling, by covering the entire population of transactions or events, rather than a subset or sample, and by identifying trends, anomalies, or exceptions that may indicate risks or issues. The other options are not features of continuous auditing that provide the best level of assurance over traditional sampling, but rather different aspects or benefits of continuous auditing, such as reporting frequency (A), reliability (B), or complexity (D).