Helene starts at an elevation of 27 feet above sea level and descends 32 feet. To find the elevation of base camp, we can perform the following calculation:
Initial elevation: 27 feet Descent: 32 feet
New elevation = Initial elevation - Descent New elevation = 27 feet - 32 feet New elevation = -5 feet
This means that base camp is 5 feet below sea level.
So, the correct answer is: 5 feet below sea level.