Final answer:
Closed Hash Table because it can provide constant time search performance (O(1)) and operates efficiently with static data sets. The correct option is B.
Step-by-step explanation:
The subject of this question involves data structures used in the computer science field, specific to the context of databases and the performance of exact match queries. Since there are no inserts or deletes, implying that the data is static, and the requirement is to perform exact match queries against this data stored in main memory, we would consider the characteristics of each data structure option given:
Binary Search Tree: Offers O(log n) search time if balanced.
Closed Hash Table: Provides O(1) average search time, regardless of the data size.
Linear Index: Generally exhibits O(n) search time but can vary based on the implementation.
B+ Tree: Commonly used in databases for its ability to reduce I/O operations.
Considering the data is static and perfect for pre-processing, a Closed Hash Table would be the most efficient structure, providing constant time search performance under ideal conditions. So, the correct option is the Closed Hash Table, due to its potential for O(1) search time and the static nature of the database which eliminates concerns over rehashing costs.