Answer;
A. Using the same restriction enzyme for cutting the desired gene and the vector and using ligase for pasting the gene into the vector.
In genetic engineering the cutting of the desired gene from its genome, then cutting the vector genome and pasting the gene into it is carried out using the same restriction enzyme for cutting the desired gene and the vector and using ligase for pasting the gene into the vector.
Explanation;
Genetic engineering involves adding a new DNA to an organisms with a goal of adding one or more new traits that are not already found in that organism.
It involves ; the isolation of DNA fragments from the donor organism; the insertion of an isolated donor DNA fragment into a vector genome and the growth of recombinant vector in an appropriate host.