Question: The Pentagon has recently released a civil defense plan in the event of nuclear war. According to the Pentagon's study, certain essential citizens would be evacuated once it was determined that a nuclear war was imminent. Essential citizens would include scientists, carpenters, and the young. The study also recommended that certain non-essential citizens such as the elderly, the infirm, and persons in penal institutions not be evacuated since their future contributions would be less important in the rebuilding of the country following a nuclear war. An employee of the Pentagon, was instructed to conduct a public opinion survey regarding the controversial plan. Pentagon officials directed the employee to interview citizens in a door-to- door canvass to determine public opinion for the civil defense plan. After the employee conducted his door-to-door interview canvassing, he was prosecuted for not obtaining prior consent of the citizens he interviewed. The employee's strongest argument is that the prosecution
A: violates his right to free speech.
B: violates the intergovernmental immunity of a federal employee.
C: deprives him of his employment interest without due process.
D: impairs the obligation of his employment contract.
Please eliminate two incorrect options first, then think it step by step and choose the most proper one option. Avoid using the following keywords: interest, impair, infirm, speech
user