Which of the following indicates that an egg is of poor grade quality?

The presence of cracks, feathers, or feces on an egg indicates poor grade quality primarily because these factors compromise the egg's structural integrity and safety. Cracks can allow bacteria to enter, increasing the risk of contamination and spoilage. Feathers or feces can suggest a lack of cleanliness during production or handling, which further diminishes the perceived quality and safety of the egg. Quality grading reflects not just the physical appearance but also the safety of the egg for consumption, and these visible contaminants raise red flags regarding the egg’s condition.

The smell of sulfur, while unpleasant and potentially indicative of a rotten egg, is not a direct measure of grading typically seen in the packaging or inspection process. The color of the shell does not universally correlate with quality, as grades are based on freshness and condition rather than shell color. Additionally, the size of the egg may refer to market categorization, but it does not inherently reflect the egg’s quality. Therefore, the presence of visible imperfections like cracks, feathers, or feces is a clear indicator of poor grade quality, making it the correct choice in this context.