What does "to speak to" in the last sentence of the second paragraph mean

A．Sometimes people will conceal what they think when being questioned by the market researchers.
B．Stephen Kosslyn and Gerald Zaltman overlook the experiments and criticize the purpose of the study.
C．Harvard researchers have found the corresponding relations between people's brain and behavior.
D．There are many large organizations endorsing and financing the Harvard group's further investigation.

A．Reading the Mind of the Market
B．Controlling the Consumers' Preferences
C．Improving the Styles of Advertising
D．Finding Out the Way to Predict