Which of the Following Statements About Plasmids Is False

Which of the following statements about plasmids is false?

A) Molecular biologists often use plasmids to generate cell lines that make useful products for medical applications.
B) Plasmids are commonly shared among cells by horizontal gene transfer mechanisms.
C) Plasmids are nonchromosomal DNA segments found in bacteria and a number of eukaryotic cells.
D) If present, plasmids are always essential to cell survival.
E) Plasmids are easily manipulated in the laboratory.