Final answer:
To estimate the number of adult tickets sold at the zoo, we need to analyze the given graph and find the closest estimate. Based on the graph, it can be estimated that about 525 adult tickets were sold.
Step-by-step explanation:
To estimate the number of adult tickets sold, we need to look at the graph provided. Based on the graph, we can see that the number of adult tickets is between 500 and 550. Looking at the given options, the closest estimate is option C, which suggests that about 525 adult tickets were sold.