Answer:
5 negative numbers
Step-by-step explanation:
-5 -4 -3 -2 -1 0 1 2 3 4 5
1  2  3  4  5 6 7 8 9 10 11
 
        
             
        
        
        
Here is the answer, with a picture of how you do it:)
 
        
             
        
        
        
Is A & C. 
Explanation:
A. Median for sea turtles:
The set is odd, so median is the middle number - 4
The koi set had 10, even number, so the median for the koi is the average of the 2 middle: 4+3=3.5
Turtles > koi
C. The ages of koi are more spread out - 10. The turtles are only 5.