Final answer:
Plasmids are essential for plastic degradation as they can carry genes for enzymes that break down specific compounds like plastics, and these plasmids can spread between bacteria, enhancing the degradation capacity across populations.
Step-by-step explanation:
Based on the observation of bacteria breaking down plastic, what can be inferred about the nature of the plasmids? The answer to this question would be B. Plasmids are essential for plastic degradation. Plasmids are extra-chromosomal DNA found in bacteria, which can carry genes coding for enzymes that help in the degradation of atypical compounds, such as some plastics. Since plasmids can contain genes not essential for normal growth but advantageous under certain conditions, bacteria harnessing plasmids with these specific degradation capabilities would exhibit the ability to break down plastic. Moreover, these plasmids can be transferred between bacteria through horizontal gene transfer (HGT), potentially spreading the capacity to degrade plastic across various bacterial populations.