The Actual Cultural Differences Between Northern and Western Europeans on the One

The actual cultural differences between Northern and Western Europeans on the one hand and Southern and Eastern Europeans on the other, Walton and Rockoff imply

A) made little difference for the prejudices of native-born Americans.
B) shaped the ways native-born Americans treated immigrants profoundly.
C) determined whether native-born Americans treated the immigrants with prejudice.
D) were minimal.