Final answer:
A synergistic relationship between two antibiotics occurs when their combined effect is greater than the sum of their individual effects, often due to different mechanisms of action complementing each other to enhance bacterial inhibition or cause bacterial cell death. Therefore , the correct answer options is b)
Step-by-step explanation:
The best explanation for a synergistic relationship between two different antibiotics, such as trimethoprim and sulfamethoxazole (Bactrim), which individually exert bacteriostatic inhibition, is that combined they become bactericidal and provide a more effective treatment against bacterial infections.
Synergistic interaction means the two antibiotics work together in a way that enhances their effect, which can be the result of different mechanisms of action that complement each other.
For example, if one antibiotic inhibits bacterial cell wall biosynthesis and another inhibits a different target such as folic acid synthesis, their combined action can lead to a more complete inhibition of bacterial growth or directly cause bacterial cell death.