Final answer:
The ratio of spiders to rats is 12:6 or 12/6.
Step-by-step explanation:
A ratio is a comparison of two quantities. In this case, we are comparing the number of spiders to the number of rats. The correct ratio is option C, 12:6. This means that for every 12 spiders, there are 6 rats. It can also be written as 12/6.