Final answer:
A B+ Tree is the best choice for a system that performs exact match queries, supports inserts and deletes in a dynamic database, and is stored in main memory.
Step-by-step explanation:
The system described in the question, which performs exact match queries only and supports inserts and deletes in a dynamic database, can be implemented using a B+ Tree. A B+ Tree is a balanced search tree that is commonly used in databases because it allows for efficient searching, inserting, and deleting of data. It keeps the data sorted, making it possible to perform binary searches for exact matches. Additionally, B+ Trees are designed to be stored in main memory, making them ideal for working with large data sets.