A Gene Does Not Contain the Necessary Restriction Enzyme Sites

A gene does not contain the necessary restriction enzyme sites for cloning into a plasmid vector. What is a possible option?

A) Increase the amount of gene used.
B) Add linkers to generate new restriction enzyme sites.
C) Use a cosmid as a cloning vector.
D) Use dideoxy sequencing to obtain the sequence of the gene.
E) Cut the DNA with a blunt end cutter.