`{:("Column A"," Column B "),("a. s & p-block"," i. Inner transition elements"),("b. d-block"," ii. s-block elements"),("c. f-block"," iii. Transition elements"),("d. group-1 and group-2" ,"iv. Representative elements"):}`

Answer

To match the items in Column A with those in Column B, we can analyze the characteristics of each block of elements and their classifications:

1. **s & p-block (Column A, a)**:
- The s and p blocks of the periodic table are commonly referred to as the **representative elements**. This is because they include the main groups of the periodic table where the outermost electrons are in the s or p orbitals.
- **Match**: a → ii (s-block elements).

2. **d-block (Column A, b)**:
- The d-block elements are known as the **transition elements**. This is due to their position in the periodic table, where they transition between the s-block and p-block elements.
- **Match**: b → iii (Transition elements).

3. **f-block (Column A, c)**:
- The f-block elements are referred to as **inner transition elements**. This is because they are located below the main body of the periodic table and include the lanthanides and actinides.
- **Match**: c → i (Inner transition elements).

4. **group-1 and group-2 (Column A, d)**:
- Group 1 and Group 2 elements are part of the **s-block elements**. Group 1 is known as alkali metals, and Group 2 is known as alkaline earth metals.
- **Match**: d → ii (s-block elements).

Now, summarizing the matches:
- a → ii (s & p-block → Representative elements)
- b → iii (d-block → Transition elements)
- c → i (f-block → Inner transition elements)
- d → ii (group-1 and group-2 → s-block elements)

### Final Matches:
- a → iv (Representative elements)
- b → iii (Transition elements)
- c → i (Inner transition elements)
- d → ii (s-block elements)