The sum of the digits hash function classifies the data into 10 different buckets thus making it the highest.

In dynamic hashing, lookup involves an additional level of indirection. The rest of the options are the advantages of dynamic hashing.

Dynamic hashing is also called as extendable hashing because it can accommodate the growth and shrinkage of the database.

We can perform lookup, insertion and deletion on a dynamic hash structure.

Dynamic hashing allows us to accommodate the growth of the database and the shrinkage of the database by allowing us to change the hash function dynamically.

The space overhead in dynamic hashing is less than that of static hashing. This is because the hash function is chosen based on the size of the file at some anticipated point in the future.

Hash structures are not the best choice for search keys on which range queries are likely because the range queries might contain different values of the search keys which might result in improper placement in the hash table.

The form of dynamic hashing that avoids the additional level of indirection is called as Linear hashing. This has more overflow buckets than extendable hashing.

The frequency of insertion and deletion has to be taken into consideration while choosing an indexing technique. The frequency of insertion and deletion determines the hash index.

The sum of digits modulo 2 classifies the data into only 2 buckets i.e. 0 and 1.