Hello everyone

I have a problem to find highest natural frequency

question : There are 3 configurations with different possible layouts for ribs. Find the configuration with the highest first natural frequency. What is the first natural frequency for that configuration? (in Hz, 2 decimal places)

Material: PET, from the Plastics category of the SolidWorks Materials library.
Fixtures: Fixed hinges on 4 faces noted A
Mesh: Standard, High quality.

I have finished it ,but not sure if I am right (please refer to my finished simulation), if wrong,how can I calculate it ?

by the way,my result is 95,54 Hz, thanks ! 

Is my answer correct ?