Answer:
Roberto: Quiero trabajar como voluntario el próximo verano. Julio: Yo tengo pensado viajar por Europa.
Step-by-step explanation:
“Tener pensado” means to plan, to intend to do something, or to think of doing something. According to the context, this is the phrase that best completes the sentence because Roberto first expresses his desire to work as a volunteer next summer and Julio continues the conversation expressing his future plans too: “Yo tengo pensado viajar por Europa,” which can be translated into “I intend to travel around Europe”