Euthanasia, often referred to as "mercy killing," is the practice of intentionally ending a life to relieve pain and suffering. However, its legality varies from country to country.

Option 1: Austria does not legally permit euthanasia. Only passive euthanasia, withdrawal of life support with the person`s consent, is somewhat acceptable.

Option 2: Switzerland — Assisted-suicide (a person providing the means for someone to end their own life), is legal here but euthanasia as such is not officially legal.

Option 3: The Netherlands — This is the correct answer. The Netherlands was the first country to legalize euthanasia. They have clear, stringent laws and procedures to regulate the practice ensuring it is performed ethically.

Option 4: Canada — The practice has only been legal in Canada since 2016. Therefore, it is not the first country to have done so.

Therefore, we understand that The Netherlands were pioneers in legalizing euthanasia, setting standards and laws for other countries to follow.