Explanation:

Let's go through each part of the sentence:

- A: "Volkswagen CEO Herbert Diess was told"

This part is correct. It provides the subject and the initial action.

- B: "with the existence of cheating software"

Incorrect preposition. It should be "about" instead of "with."

- C: "in cars two months before regulators exposing the multi-billion"

Verb form issue. "Exposing" should be "exposed" to maintain past tense consistency.

- D: "dollar exhausting emission scandal, German magazine Der Spiegel reported."

"Exhausting" should be "exhaust" to describe the type of emission legally.

The correct part without errors:

- A: "Volkswagen CEO Herbert Diess was told"