Final answer:
The increased use of antibiotics in hospitals is a reason for the increased number of drug-resistant bacteria being found in hospitals. Therefore, the correct option is A.
Step-by-step explanation:
One of the main reasons for the increased number of drug-resistant bacteria being found in hospitals is the increased use of antibiotics in hospitals. Antibiotics have been widely prescribed, resulting in the natural selection of resistant forms of bacteria. Additionally, patients sometimes do not complete their full antibiotic prescription, allowing the resistant forms to survive and multiply.