In a partitioned distributed system, which approach prioritizes strong consistency at the expense of availability?

• A. AP
• B. CP
• C. CA
• D. CP and AP together

Answer: (D)

At a partition, the important trade-off is between keeping data strictly in sync (consistency) and keeping the system responding to requests (availability). The CP approach prioritizes strong consistency across replicas even if that means some requests are denied or delayed during a partition to avoid serving conflicting data. In other words, it tolerates reduced availability to ensure correctness of data.

AP, by contrast, stays highly available but may return stale or divergent data because it relaxes consistency in order to keep responding. CA isn’t practical in a partitioned network because partitions are expected in distributed systems, so you don’t typically count on both consistency and availability without considering partition tolerance.

Combining CP and AP together isn’t a valid CAP stance under partitions, since you can’t simultaneously guarantee both strong consistency and high availability when the network splits. So the approach that best fits “strong consistency at the expense of availability” is CP.