Correct Answer: BGiven the scenario where there are 1000 meeting rooms equipped with motion sensors reporting their status every second, the most appropriate database type would be one that can handle massive volumes of rapidly changing, potentially unstructured data. A NoSQL database fits this requirement well. NoSQL databases are designed to manage large amounts of data and can be scaled horizontally across many servers, which is crucial for handling data from multiple sources in real-time. Additionally, NoSQL databases are flexible, allowing the storage of various types of data without a fixed schema, making it easier to adapt to different kinds of sensor data. Other options, such as flat files, relational databases, and blobstores, do not offer the same level of scalability, flexibility, and ease of handling such large, rapidly evolving datasets.