Final answer:
The difference in height between the pelican flying at 20 ft above sea level and the fish swimming at 23 ft below sea level is 43 ft, but due to a probable typo in the question, the closest correct option provided is 40 ft (option a).
Step-by-step explanation:
The question asked is a mathematics problem involving the calculation of the difference in height between various animals above and below sea level. The seagull is flying at 80 ft above sea level, the pelican is flying at 20 ft above sea level, and the fish is swimming at 23 ft below sea level. The question provides contradictory differences in heights, but looking at the options given, we are to determine which option correctly states the difference in height between the pelican and the fish.
The correct difference in height is calculated by subtracting the pelican's height from the fish's depth. Since the pelican is 20 ft above sea level and the fish is 23 ft below sea level, the total difference is 43 ft. However, since none of the options match this result, we can assume there may have been an error in the stated differences. Given that the only feasible answer that matches these conditions provided in the options is 40 ft (option a), we can conclude that this is most likely a typographical error in the question.