The Max Size (MB) limit isn't strictly enforced. Storage size is checked only when Query Store writes data to disk. This interval is set by the Data Flush Interval (Minutes) option. If Query Store has breached the maximum size limit between storage size checks, it transitions to read-only mode.
Incorrect Answers:
C: Statistics Collection Interval: Defines the level of granularity for the collected runtime statistic, expressed in minutes. The default is 60 minutes. Consider using a lower value if you require finer granularity or less time to detect and mitigate issues. Keep in mind that the value directly affects the size of Query Store data.
Reference:
https://docs.microsoft.com/en-us/sql/relational-databases/performance/best-practice-with-the-query-store