The faulty prediction is more likely to be a result of sampling error and the correct option is C.
Reasoning:
Stratified sampling: The newspaper used a stratified sample, ensuring representation of key demographics in the voting population. This reduces bias compared to a random sample without stratification.
Question-wording: No information suggests biased question wording pushing voters towards candidate A.
Systematic bias: The description doesn't suggest any systematic issue in the sampling method that would consistently favor or disfavor a specific candidate.
Sampling error: Even with a good sampling method, random chance during sample selection can lead the sample to be slightly different from the population. This natural variability can explain the discrepancy between the prediction and the actual results.
Therefore, while bias is always a possibility, the available information points towards sampling error as the more likely explanation for the inaccurate prediction.