Final answer:
The resource pool of a country is determined by the availability and quality of raw materials, personnel, training systems, and capital. The option not discussed in the text as a factor determining resource pool is 'the size of the population'.
Step-by-step explanation:
When evaluating the resource pool of a country, several factors of production come into play. These are essential for understanding the production capacities and economic potential of a country. According to the provided text and options, the factors that determine a country's resource pool include the quantity, quality, and accessibility of raw material (A), the quantity, quality and cost of personnel available (B), the training and development system available (C), and the cost and amount of capital available to firms (D). However, out of the choices provided, the correct option that is not discussed as a factor in the text is A. the size of the population, since the factors mentioned focus on the quality and not just the quantity of personnel, and also on the accessibility and cost of various resources such as raw materials and capital.