Step 1: Recall the case.
Parmanand Katara v. Union of India (1989) is a famous Supreme Court case about Article 21 of the Constitution, which protects the right to life.
Step 2: Understand the problem it solved.
Earlier, doctors and hospitals would sometimes delay treating an injured person, especially in accident or crime cases, while they waited for police paperwork or medico-legal formalities. This delay could cost lives.
Step 3: See what the Court held.
The Court said every injured person, whether innocent or even a criminal, has the right to immediate medical care. Doctors, both government and private, must give emergency treatment first and not wait for legal formalities.
Step 4: Link it to a right.
This makes emergency medical care a part of the right to life under Article 21. So the case is best linked to the right to emergency medical care.
Step 5: Reject the other options.
Right to speedy trial, the general right to life and personal liberty stated alone, and right to a clean environment are linked to other cases. The sharpest and most specific match here is emergency medical care.
Step 6: State the answer.
The case is primarily about the right to emergency medical care.
\[ \boxed{\text{Right to emergency medical care}} \]