Which of the following is most clearly an example of dialogue?

Read the excerpt from infinite jest. three faces have resolved into place above summer-weight sportcoats and half-windsors across a polished pine conference table shiny with the spidered light of an arizona noon. these are three deans—of admissions, academic affairs, athletic affairs. i do not know which face belongs to whom. which line of text supports the idea that hal is meeting the college deans for the first time? a. three faces have resolved into place above summer-weight sportcoats. . b. . half-windsors across a polished pine conference table shiny with the spidered light. . c. these are three deans—of admissions, academic affairs, athletic affairs. d. i do not know which face belongs to whom.