I think that the best answer is C, it is not influenced by economic conditions.
I hope this helps!
<span>The size of plasmids<span> ranges
between 1 and 200 kbp (kilo-base pairs) and a DNA fragment that can be
inserted into a </span>plasmid vector is up
to 20 kbp. Artificially constructed plasmids are often used as vectors in
genetic engineering to clone and amplify (or express) particular genes. </span>
