Question

read each line and determine if it was said by el vendedor, una persona de la comunidad, or both. ¿qué quieres cambiar? el vendedor una persona de la comunidad

Explanation:

The phrase "¿Qué quieres cambiar?" translates to "What do you want to exchange/change?". This is a question a vendor would ask a customer in a transaction context, as it relates to facilitating a product exchange, which is part of a vendor's role. A community member would not typically use this phrase in this transactional sense.

Answer:

el vendedor