Final answer:
The student can make four different selections of three questions from the four options available, based on the mathematical concept of combinations.
Step-by-step explanation:
The student's question relates to the mathematical concept of combinations. Since a student must choose any three essay questions from a set of four, we're looking at the number of possible combinations. The formula to calculate combinations is C(n, k) = n! / (k!(n-k)!), where 'n' is the total number of items to choose from, 'k' is the number of items to choose, and '!' stands for factorial.
In this instance, n=4 (four questions) and k=3 (three selections), so the calculation would be: C(4, 3) = 4! / (3! * (4-3)!) = 4 / 1 = 4. Therefore, there are four different selections of questions that can be made.