Answer:
The correct answer is option A. demonstrates that the E. coli cultures were viable.
Explanation:
In this lab experiment or culture, Plate I and plate III demonstrate, that E.coli bacteria can grow both in the presence and absence of plasmid DNA if ampicillin is not there.
So, which means that plasmid DNA is not required for the growth of E.coli in absence of ampicillin. The presence of growth in wild type (plate 1) and a plasmid containing bacteria (plate 3) in media without ampicillin shows that bacteria are viable in nature.