The physical disposition of material is characterized as either ____ or ____.

The correct answer is that the physical disposition of material is characterized as either dense or sparse. This terminology relates to how closely packed the particles in a material are, which can greatly influence its behavior in terms of fire dynamics.

Dense materials have closely packed particles, which can affect heat retention and transfer, combustion characteristics, and the overall behavior of fire when it interacts with such materials. Conversely, sparse materials have more space between particles, which can influence airflow and combustion efficiency.

The other choices, such as thick or thin, large or small, and rough or smooth, do not directly address the crucial aspect of material disposition in relation to fire behavior. These terms may describe other properties of materials, but they do not adequately capture the specific characteristics relevant to the interaction of materials with fire and heat.