Question 643 Deck General

The correct answer is A) Hook block. In the illustration D045DG of a 30-ton pedestal crane, the item labeled "D" refers to the hook block. The hook block is the component that supports the crane's hook and allows it to move freely to lift and lower loads. This is the correct identification based on the typical components and terminology used in crane diagrams and illustrations. The other answer choices are incorrect because they refer to different parts of the crane that are not specifically labeled as item "D" in this illustration. The rider block, heel block, and gin block are other crane components, but they are not the item indicated by the letter "D" in this specific diagram.