“The main challenge is to carry out the work while keeping the installation operational this year for its users”, explains Sébastien Evrard, project leader for the PS East Experiment Area renovation.

Classify the level of management that Sébastien Evrard holds based on the above sentence.  Your choices are: Top-level, Middle-level, Lower-level, Non-management, External
Based on the provided sentence, Sébastien Evrard's management level can be classified as Middle-level. As the project leader, they likely have decision-making authority and oversee the project but still report to upper-level management.