Final answer:
The Gypsum Construction Handbook recommends storing gypsum panel products stacked flat on risers in the center of the room, as it is the safest method providing even weight distribution and protection from moisture.
Step-by-step explanation:
The safest way to store gypsum panel products on a jobsite, according to the Gypsum Construction Handbook, is A. stacked flat on risers in the center of the room. This is because stacking the panels flat will distribute the weight evenly and prevent warping or damage. The use of risers will ensure that the panels are kept off the ground, which is important in a dry room to prevent any potential moisture damage.
Storing gypsum panels on edge or in vertical stacks against walls or with space between the stacks and walls, while sometimes practiced, does not offer the same level of safety and stability that proper flat stacking provides. Employing warning tape or signage may indicate potential hazards but does not inherently add to the safety of the panel storage itself.