Use your knowledge of explicit contracts to identify which restriction of an explicit contract is identified in the following example. A drug-free workplace policy says that it conducts pre-employment drug testing on all new hires, it uses a zero-tolerance approach for dealing with policy violations, and it mandates participation for all employees. How would you evaluate the effectiveness of this policy? The policy as written is effective. To be more effective, the terms of the written policy should be administered on a case-by-case basis. The policy is completely ineffective. To be more effective, participation should be voluntary