Step 1: Understanding the Question:
This current affairs question focuses on international laws, social reforms, and significant global legislative developments.
We need to identify the country/region that approved a landmark law in May 2025 legalizing assisted dying for terminally ill adults.
Step 2: Detailed Explanation:
$\bullet$ Assisted dying has been a subject of intense ethical, legal, and political debate globally for decades.
$\bullet$ In May 2025, a historic legislative shift occurred when England and Wales approved a law legalizing assisted dying.
$\bullet$ This landmark legislation allows terminally ill adults who meet strict eligibility criteria (such as having a limited life expectancy of 6 months or less and possessing full mental capacity) to make a voluntary choice to end their lives.
$\bullet$ The bill underwent extensive debate in the UK Parliament, with significant focus on safeguards to protect vulnerable individuals.
$\bullet$ While other countries like Canada and parts of Australia already had existing laws, this development represents a major change for the United Kingdom.
$\bullet$ Therefore, England and Wales is the correct region associated with this legislative milestone in May 2025.
Step 3: Final Answer:
England and Wales approved the landmark law allowing assisted dying for terminally ill adults in May 2025.
Therefore, the correct option is (C).