Answer
No, ProjectID is not a determinant
Work Step by Step
A determinant is an attribute (or set of attributes) on which some other attribute is functionally dependent.
ProjectID alone does not determine EmployeeName.
ProjectID alone does not determine EmployeeSalary, because many employees can work on the same project.
Therefore, ProjectID is not a determinant.
The determinants in this table are:
(ProjectID, EmployeeName) → EmployeeSalary (primary key)
EmployeeName → EmployeeSalary (partial dependency)