To Position a Gene in an Expression Vector Downstream from a Promoter

To position a gene in an expression vector downstream from a promoter (i.e., perform directional cloning) , it is best to:

A) use the largest plasmid available.
B) treat the gene with DNase I.
C) restrict both the gene and the plasmid with one restriction endonuclease and then screen all colonies for those that express the gene.
D) restrict each end of the DNA fragment (gene) with a different restriction endonuclease and do likewise for the plasmid.
E) use a vector with two sites for the same restriction endonuclease.