The correct answer is option 'D', Extra-judicial killings.

The 'Justice (retd) Shashi Kant Commission' is primarily related to the issue of extra-judicial killings. Let's understand this in detail:

Introduction:
- The Justice (retd) Shashi Kant Commission is a commission set up to investigate cases of extra-judicial killings in the state of Punjab, India.
- Extra-judicial killings refer to the unlawful killing of individuals by state agents without due process of law.

Background:
- Punjab, in the 1980s and 1990s, witnessed a period of insurgency and violence due to the Khalistan movement.
- During this time, there were several instances of extra-judicial killings by the police and security forces.
- These killings were carried out under the pretext of maintaining law and order and combating terrorism.

Formation of the Commission:
- In 2017, the Punjab and Haryana High Court ordered the formation of the Justice (retd) Shashi Kant Commission.
- The commission was set up to investigate cases of extra-judicial killings and to provide justice to the victims and their families.

Objectives of the Commission:
- The primary objective of the commission is to identify cases of extra-judicial killings in Punjab and bring the perpetrators to justice.
- The commission aims to provide compensation and relief to the families of the victims.
- It also aims to recommend measures to prevent future instances of extra-judicial killings and to reform the police system.

Role of the Commission:
- The commission conducts thorough investigations into the reported cases of extra-judicial killings.
- It collects evidence, examines witnesses, and gathers all relevant information related to each case.
- Based on its findings, the commission prepares a detailed report with recommendations for further action.

Impact and Significance:
- The Justice (retd) Shashi Kant Commission plays a crucial role in addressing the issue of extra-judicial killings in Punjab.
- It helps in ensuring justice for the victims and their families, who have suffered due to these unlawful acts.
- The commission's recommendations for police reforms can lead to the prevention of future instances of extra-judicial killings and the improvement of the overall law and order situation in the state.

Conclusion:
The Justice (retd) Shashi Kant Commission is primarily related to the issue of extra-judicial killings in Punjab. It aims to provide justice to the victims, recommend measures for police reforms, and prevent future instances of such killings. Its formation serves as an important step towards upholding the principles of justice and human rights in the state.