A DNA molecule produced by combining DNA from different sources is known as (ONLY ANSWER IF YOU KNOW ITS RIGHT)

a mutant.

a hybrid.

a polyploid.

recombinant DNA.

A DNA molecule produced by combining DNA from different sources is known as recombinant DNA.

Explanation:

Recombinant DNA (rDNA) can be obtained by coupling DNA fragments from different sources, a process that is performed at the restriction site level and uses enzymes.  

Once rDNA has been designed —cutting out fragments of DNA that are then reassembled— it must be brought to a specific location in the cells, to be copied and expressed, using means of transport called vectors.

DNA recombination is performed in biotechnology laboratories specialized in the manipulation of genetic material.

The other options are not correct because:

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.

the answers are a and c