The Accompanying Table Shows Cassie's Preference Ranking for Different Brands

The accompanying table shows Cassie's preference ranking for different brands of boots in both 2011 and 2012. Her preferences are ranked from 1 to 4, where 4 is her most-preferred brand and 1 is her least-preferred brand. In 2011, one of Cassie's ten close friends owned a pair of Ugg boots. In 2012, six of Cassie's eleven close friends owned a pair of Ugg boots. Based on this information, which effect would likely explain the change in Cassie's preference ranking for Ugg boots from 2011 to 2012? $\begin{array}{lll}\text { Brand of Boots }&2011 \text { Preference Ranking }&2012 \text { Preference Ranking }\\\text { Adidas } & 3 & 2 \\\text { Clarke's } & 4 & 3 \\\text { Ecco } & 1 & 1 \\\text { Ugg } & 2 & 4\end{array}$

A) social norming effect
B) superiority effect
C) bandwagon effect
D) friendship effect
E) consumer preference effect