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[ Option B ]

A hash table is typically implemented using an array. The hash function converts a key into an array index, and the value is stored at that index in the array.
Arrays are used because they provide fast random access, which allows insertion, deletion, and searching operations in O(1) average time.

[ Option C ]

A Hash Table provides very fast searching, insertion, and deletion, generally in O(1) time on average, because it uses a hash function to compute the index of the element.
Hash Table stores data in an associative manner using a hash function to compute an index where the value is stored.

[ Option C ]

In a chained hash table (external hashing), each slot in the hash table holds a linked list of all elements that hash to the same index. This makes deletion easier because elements can be removed from the linked list without affecting other entries in the main hash table array.
Unlike in open addressing, stores all elements directly in the array itself, which makes deletion more complex.
Another advantage of external hashing is it handles collisions efficiently, multiple elements can exist at the same slot without affecting other slots.

[ Option D ]

Given:

• Hash Function: H(K) = K mod 10
• Keys (in-order insertion): [40, 27, 19, 48, 7]
• Collision Resolution: Linear Probing
• Memory addresses available: 0 to 9 (single digit)

Step-by-step Insertion with Linear Probing:
Insert 40:

• H(40) = 40 % 10 = 0
• Store at address 0

Insert 27:

• H(27) = 27 % 10 = 7
• Store at address 7

Insert 19:

• H(19) = 19 % 10 = 9
• Store at address 9

Insert 48:

• H(48) = 48 % 10 = 8
• Store at address 8

Insert 7:

• H(7) = 7 % 10 = 7
• Address 7 is already occupied (by 27)

Use linear probing (check next available slot)
Try address 8 →  Already taken (by 48)
Try address 9 →  Already taken (by 19)
Try address 0 →  Already taken (by 40)
Try address 1 →  Free
So, 7 is stored at address 1