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.