Artificial selection is the approach which can be used to isolate (GFP) gene.
Polymerase chain reaction is useful for amplification of the gene of interest.
Gel electrophoresis is a process in which gel fragments are separated on the basis of their size for isolation and identification of specific gene of interest a special technique like DNA fingerprinting or polymerase chain reaction is required.
Artificial selection isolates the gene of interest so as to produce offsprings of interest. The genes are isolated from both of the parents to produce an offspring of interest.
Gene cloning involves the complete creation of new gene which is identical to the parent gene.
Therefore, artificial selection involves the isolation of green fluorescent protein (GFP) gene from the jellyfish DNA.