Correct answer: A. Lack of clarity of law
Explanation: Direct answer: Option A, lack of clarity of law. Equal application is important, but it is not enough by itself. A fair legal system also requires that people can know what the law says, what conduct is allowed or prohibited, and what procedure authorities must follow. Reasoning step by step: the law applies to everyone; citizens cannot understand or find it; they cannot reliably follow it or challenge misuse; therefore clarity and public knowledge are missing. Option A is correct. Option B, lack of voting machine, concerns election equipment and does not explain an unclear law. Option C, lack of tax collection, concerns government revenue and is unrelated. Option D, lack of campaign platform, concerns political communication and is not the legal weakness described. A law that is secret, vague, or unknowable can permit arbitrary action even if officials claim to apply it equally. Memory cue: good law must be equal, clear, public, and reasonably predictable.