Quorum-based protocols essentially enforce consistency between replicas of the same data item by means of three configurable parameters N (the number of nodes to which a data item is replicated), R (the minimum number of nodes that should respond before a read operation for a data item can be considered as completed), and W (the minimum number of nodes that should receive the updated value before a write operation for a data item can be considered as completed), with R ≤ N and W ≤ N. Which statement is not correct?

a. A higher N allows for more parallelism, but at the same time increases the overhead if one needs to keep all N replicas permanently consistent.

b. A higher R increases the chance that the set of replicas that is returned by these R nodes contains an up-to-date version of the data item.

c. The higher W is, the faster the write performance, since the response time is determined by the fastest of these W nodes.

d. By manipulating R and W, the database administrator can decide on the tradeoff between performance and consistency, but also on the tradeoff between read performance and write performance.