I didn't agree with his ____________ at all regarding the future of the ship-building industry.

The correct answer is "conclusion." In the context of the sentence, "conclusion" refers to the final judgment or inference drawn by someone based on evidence or reasoning. When someone expresses a viewpoint about the future of an industry, they typically arrive at a conclusion from the data or arguments presented. Therefore, not agreeing with the "conclusion" indicates that there was a disagreement on the assessment or interpretation of the situation concerning the ship-building industry.

The other options can be considered in their meanings: "decision" implies a choice made, which isn't directly fitting as the speaker is disagreeing with an interpretative or analytical stance rather than a decision made. "Argument" refers to the reasoning behind a viewpoint; however, in this case, the sentence implies disagreement is with the final point made, not the process leading to it. "Statement," while a general term that could apply, lacks the specificity associated with drawing a conclusion based on an argument or evidence, making it a less appropriate choice.