The correct answer is option 'C' - ORG.

1. Introduction:
In assembly language programming, the ORG directive is used to specify the starting address of a particular segment, block, or code. It instructs the assembler to allocate memory starting from the declared address.

2. ORG Directive:
The ORG directive stands for "origin" and is typically followed by a memory address. It tells the assembler to start allocating memory from the specified address onward. This directive is essential for organizing the memory layout and ensuring that different parts of the code or data are located at the desired locations.

3. Memory Allotment and Addressing:
Memory allotment refers to the process of reserving memory space for storing variables, constants, instructions, and other data elements. Each memory location has a unique address that allows the processor to access and manipulate the data stored in it.

4. Segment/Block/Code:
In assembly language programming, a program is divided into different segments or blocks to manage the code and data efficiently. A segment can contain subroutines, data declarations, or other code sections. The term "code" generally refers to the executable instructions of a program.

5. Starting Address:
The starting address is the memory location where a particular segment, block, or code should begin. By specifying the starting address using the ORG directive, the assembler ensures that the allocated memory starts from the desired location.

6. Importance of ORG Directive:
The ORG directive is crucial for programs that require specific memory layouts, such as embedded systems or device drivers. It allows programmers to control the placement of code and data in memory, ensuring efficient execution and access.

7. Usage Example:
Here's an example of how the ORG directive is used in assembly language:

```
ORG 1000h ; Start allocating memory from address 1000h
data DB 10 ; Allocate 1 byte of memory for variable 'data'
code:
MOV AX, 5 ; Allocate 2 bytes for the instruction 'MOV AX, 5'
ADD AX, BX ; Allocate 3 bytes for the instruction 'ADD AX, BX'
```

In the above example, the ORG directive specifies that memory allocation should start from address 1000h. The subsequent instructions and data declarations are then allocated memory starting from that address.

8. Conclusion:
The ORG directive in assembly language programming is used to specify the starting address for memory allotment of a particular segment, block, or code. It allows programmers to control the memory layout and ensure that the desired memory addresses are used for storing data and instructions.