The Edgeworth Box Version of Interpersonal Trade Requires the Individuals

The Edgeworth box version of interpersonal trade requires the individuals to be in close proximity of one another.

A) True, that way they can see each other's endowments and prices.
B) False, being in close proximity is not required for mutually beneficial trade to occur in the Edgeworth box.
C) True, the Edgeworth box only works when there folks see "eye-to-eye."
D) False, although prices are only valid if they are communicated in person.