Final answer:
The correct option is C). The best way to determine a customer's needs is through direct interaction by asking questions and engaging in conversation, complemented by careful observation of body language and nonverbal cues such as eye contact.
Step-by-step explanation:
The best way to determine a customer's needs is by gathering information through careful observation and by asking questions and engaging in conversation. This approach allows for direct interaction with the customer, providing opportunities to clarify needs and preferences. Careful observation, including reading body language, can give insights into customer reactions that might not be shared verbally. One should be aware of nonverbal cues, such as avoiding eye contact, which can convey disinterest or a lack of confidence. Instead, maintaining eye contact during greetings and conversations shows engagement. During interactions, the positioning of one's body, facial expressions, and even the customer's own words can offer additional context to their needs and preferences. Additionally, consulting with professionals, conducting interviews, and using existing records are methods for gathering authoritative and relevant information for various research situations.