In LaPiere's (1934) Research with the Chinese Couple Travelling Throughout

In LaPiere's (1934) research with the Chinese couple travelling throughout the United States during a time of widespread negative attitudes toward Chinese people, the relationship between attitude and actual behaviour would have probably been stronger if LaPiere

A) inquired about the attitudes sooner.
B) had included a picture of the specific Chinese couple.
C) had conducted personal interviews.
D) had conducted the survey before the behaviour.