D-Zero has 1 million HP in the main game of Examination. The wiki entry also notes that this applies to the main game, not the Tunnels map, and that he can heal after executions, though the exact amount is unknown.

Quick detail

  • Main game HP: 1,000,000.
  • Source notes this is not the Tunnels version.
  • Community posts on the same topic also repeat the 1 million HP figure.

Note

The answer is based on public wiki/community info, so if the game gets updated, the value could change later.

TL;DR: D-Zero has 1,000,000 HP in Roblox Examination.