Final answer:
The correct nonverbal communication method used by the sales associate to acknowledge a new customer while attending to another is smiling at the customer and giving eye contact.
Step-by-step explanation:
The subject of nonverbal communication represents an important aspect of interactions in a business environment. When the sales associate was with a customer and another customer walked in, without verbally communicating, the associate could engage nonverbally. Option B, smiling at the customer & giving eye contact, and option C, smiling & saying I'll be right with you both involve nonverbal elements. However, option B is the correct answer to the question since it specifies a nonverbal response, whereas option C includes speech. Nonverbal cues such as maintaining eye contact and offering a smile communicate friendliness and acknowledgment of the second customer's presence, suggesting that the associate will assist them as soon as possible.