To effectively explore the discrepancy in reported dietary habits among high school students in urban Western Cape, the most appropriate question for Noxolo to ask would be:
"Why is there a discrepancy in the reported dietary habits of high school students in urban Western Cape?"
This question directly addresses the variance in findings from different studies and prompts an investigation into underlying factors contributing to the differences, such as cultural influences, socioeconomic status, availability of food options, and survey methodologies. The other options, while informative, do not specifically target the issue of discrepancies in reported dietary habits within the same urban context.