Which of the following statements is true about infections?

• A. Infections can be caused by bacteria, viruses, fungi, or parasites.
• B. Infections are always caused by bacteria.
• C. Infections only occur in the respiratory system.
• D. Infections are always beneficial to the host organism.

Answer: (A)

Verified step by step guidance

1. Begin by understanding the definition of an infection. An infection occurs when a foreign organism enters a host's body and causes harm or disease.
2. Identify the types of organisms that can cause infections. These include bacteria, viruses, fungi, and parasites. Each type has distinct characteristics and modes of transmission.
3. Evaluate the statement that infections are always caused by bacteria. Consider the fact that viruses, fungi, and parasites can also cause infections, making this statement false.
4. Consider the statement that infections only occur in the respiratory system. Infections can occur in various parts of the body, such as the skin, gastrointestinal tract, and urinary tract, not just the respiratory system.
5. Assess the statement that infections are always beneficial to the host organism. Infections typically harm the host by causing disease or discomfort, so this statement is incorrect.