Final answer:
The most appropriate phrase to complete the dialogue is '¡Mucho gusto!', which means 'Nice to meet you'.
Step-by-step explanation:
The most appropriate phrase to complete the dialogue is ¡Mucho gusto! It is a common phrase used to express pleasure upon meeting someone for the first time. In this case, Lisa introduces herself to Isabel, and Isabel responds with '¡Igualmente!', which means 'likewise'. This exchange shows a polite and friendly interaction between the two individuals.
Learn more about Polite greetings in Spanish