instruction:
Given a passage with a question and an answer to that question, classify if the answer actually answers the question into 'yes' or 'no'. Output 'yes' if the answer answers the question and output 'no' if the answer does not answer the question.
question:
Question: Is routine preoperative lymphoscintigraphy necessary prior to sentinel node biopsy for breast cancer?
Answer: Preoperative lymphoscintigraphy adds little additional information to intraoperative lymphatic mapping, and its routine use is not justified.
answer:
no


question:
Question: Are front-of-pack symbols a reliable indicator of products with healthier nutrient profiles?
Answer: FOP symbols are being used to market foods that are no more nutritious than foods without this type of marketing. Because FOP symbols may influence consumer perceptions of products and their purchases, it may be a useful public health strategy to set minimum nutritional standards for products using FOP symbol marketing.
answer:
no


question:
Question: Is a persistently low HBV DNA level a predictor of spontaneous HBsAg clearance in patients with chronic hepatitis B?
Answer: These results suggest that a continuously low viral load is the most important factor affecting spontaneous HBsAg seroclearance.
answer:

yes