Q: Fact 1: Population density is the average number of individuals per unit of area or volume. Fact 2: Economy is affected by population size and density. Given the two facts above, what is affected by the average number of individuals per unit of area or volume?

Select from the following. 1). goats 2). economy 3). cows 4). animals 5). vegetation 6). mammals 7). bushes 8). wind
The answer is:
2).