Name a key factor that contributes to the spread of antibiotic-resistant infections.

The correct choice highlights the significant impact that the overuse and misuse of antibiotics has on the development of antibiotic-resistant infections. When antibiotics are used excessively or inappropriately, whether through overprescription for conditions that may not require them or by patients not completing their prescribed courses, it creates a selective pressure on bacteria. This pressure allows for the survival and multiplication of those bacteria that have developed resistance mechanisms.

As a result, these resistant strains become dominant, rendering common antibiotics less effective or completely ineffective for treating infections. This phenomenon not only complicates treatment for individual patients but also increases healthcare costs and contributes to the larger public health crisis of antibiotic resistance. Understanding this factor is essential for developing effective strategies to combat the rise of resistant infections and preserving the efficacy of existing antibiotics.