To determine the percentage of students who chose the amusement park, follow these steps:
1. Identify the total number of students surveyed:
[tex]\[
\text{Total students} = 286
\][/tex]
2. Identify the number of students who chose the amusement park:
[tex]\[
\text{Students who chose the amusement park} = 121
\][/tex]
3. Calculate the percentage of students who chose the amusement park:
[tex]\[
\text{Percentage} = \left( \frac{\text{Students who chose the amusement park}}{\text{Total students}} \right) \times 100
\][/tex]
4. Substitute the values:
[tex]\[
\text{Percentage} = \left( \frac{121}{286} \right) \times 100
\][/tex]
5. Simplify the calculation (using the known result):
[tex]\[
\text{Percentage} = 42.31\%
\][/tex]
Based on these steps, the correct percentage of surveyed students who chose the amusement park is:
[tex]\[
\boxed{42.31\%}
\][/tex]
Hence, the correct answer is:
[tex]\[
\text{C. } 42.31\%
\][/tex]