Answer
BUC= {4,5,6,7,8,9,10,11,12}
Work Step by Step
The set (BUC), represents the all the elements of the set B and the elements of C which are not present in set B.
From the given Venn diagram we can conclude that the regions II, III, IV, V, VI, VII represent the set (BUC). The element of these regions are 4,5,6,7,8,9,10,11,12
So, BUC= {4,5,6,7,8,9,10,11,12}