Detailed Explanation:

The Galwan Valley clash occurred on 15–16 June 2020 between Indian and Chinese troops in eastern Ladakh, resulting in casualties on both sides—the deadliest confrontation since 1975.

This violent face-off marked a significant escalation in the India-China border standoff that began in May 2020, drawing international attention to tensions along the Line of Actual Control (LAC).

Therefore, June 2020 is the correct timeline, making Option 4 the correct answer.