Vectors Such as PUC18 and Others of the PUC Series $\beta$

Vectors such as pUC18 and others of the pUC series contain a large number of restriction enzyme sites clustered in one region.Which term describes this advantageous arrangement of restriction sites?

A) palindrome
B) consensus sequence
C) multiple cloning site
D) $\beta$ -galactosidase
E) complementation