Robert didn't mince words. If a person's ideas were ill-considered, he was likely to tell them that their ideas were bad. If there was a disagreement, he plainly stated that the person with the opposing viewpoint was wrong. To some, his manner was abrasive and uncollegial and this was a source of:

Your question is missing the options. I've found the complete question online. It is as follows:

Robert didn't mince words. If a person's ideas were ill-considered, he was likely to tell them that their ideas were bad. If there was a disagreement, he plainly stated that the person with the opposing viewpoint was wrong. To some, his manner was abrasive and uncollegial and this was a source of:

A) Goal-oriented conflict.

B) Administrative conflict.

C) Interpersonal conflict.

D) Interactionist conflict.

I believe the best option is letter C) interpersonal conflict.

Explanation:

Notice how Robert is not creating a negotiable and debatable form of conflict. His intention is not to open discussions that may lead to problem-solving and the achievement of goals. His purpose is to merely state his point, claim he is right and someone else is wrong, with no consideration for the emotional distress he may cause. That is what interpersonal conflict is: a disagreement between people or groups of an organization that results in resentment and dissatisfaction.