Answer:
Option B: compounds
Explanation:
Elements can be chemically combined into compounds, therefore, a compound consists of two or more elements combined, in fixed rstios, by chemical means.
There are multiple possible answers. One is that it's mouse droppings since mice like to eat it. Another is that it's bugs and this is dangerous since they can leave larva there. The third is that they are remaining residue traces from other types of oats that were ground together and in this case it is not that dangerous.
The correct answer is <span>Variable ratio reinforcement schedule (VR)</span>