Introduction:
The highest point of their journey was 7524 feet above sea level.

Explanation:
- The question asks about the highest point of their journey among the given options.
- Let's analyze each option to determine the correct answer.

a) Mount Everest:
- Mount Everest is the highest peak in the world, with an elevation of 29,029 feet (8,848 meters) above sea level.
- However, the given options do not mention anything about climbing Mount Everest or any other mountain.
- Therefore, we can conclude that Mount Everest is not the correct answer for the highest point of their journey.

b) 7524 feet above sea:
- This option states that the highest point of their journey was 7524 feet above sea level.
- Sea level is the average level of the surface of the oceans.
- So, they reached a point that was 7524 feet higher than the average level of the oceans.
- Since this option is specifically mentioned in the question, it is the correct answer for the highest point of their journey.

c) Near the giant statue:
- This option mentions being near a giant statue.
- However, it does not provide any information about the elevation or height of the statue.
- Without knowing the specific height, we cannot determine if this option represents the highest point of their journey.
- Therefore, we can conclude that this option is not the correct answer.

d) None of the above:
- The option "None of the above" is selected when none of the given options is correct.
- In this case, option b) "7524 feet above sea" is the correct answer, so "None of the above" is not applicable.

Conclusion:
- Among the given options, the highest point of their journey was 7524 feet above sea level.
- This option is the correct answer because it is specifically mentioned in the question.