Introduction:
Linear FIR (Finite Impulse Response) filtering is a commonly used technique in digital signal processing for filtering a long sequence of data. Two popular methods for implementing linear FIR filtering on a block-by-block basis using the Discrete Fourier Transform (DFT) are Overlap Add and Overlap Save.

Overlap Add:
In the Overlap Add method, the long sequence is divided into overlapping blocks. Each block is then filtered using the FIR filter in the frequency domain. The filtered blocks are then added together, taking into account the overlap between adjacent blocks. Finally, the resulting sequence is obtained by discarding the overlapping portions.

Overlap Save:
In the Overlap Save method, the long sequence is also divided into overlapping blocks. However, in this method, the blocks are filtered in the time domain using the inverse DFT. The resulting sequence is then obtained by discarding the overlapping portions.

Comparison:
The key difference between Overlap Add and Overlap Save lies in the domain used for filtering. Overlap Add filters the blocks in the frequency domain using the DFT, while Overlap Save filters the blocks in the time domain using the inverse DFT.

Overlap Add:
- Blocks are filtered in the frequency domain using the DFT.
- Suitable for systems with a long impulse response.
- Requires more computational resources due to the DFT and inverse DFT operations.
- Overlapping portions are discarded to obtain the resulting sequence.

Overlap Save:
- Blocks are filtered in the time domain using the inverse DFT.
- Suitable for systems with a short impulse response.
- Requires fewer computational resources compared to Overlap Add.
- Overlapping portions are discarded to obtain the resulting sequence.

Conclusion:
In conclusion, Overlap Add and Overlap Save are two methods for linear FIR filtering a long sequence on a block-by-block basis using DFT. Overlap Add filters the blocks in the frequency domain using the DFT, while Overlap Save filters the blocks in the time domain using the inverse DFT. The correct answer is option 'A' - True.