Final answer:
High humidity in a dry storeroom can cause food to become unsafe due to the growth of microorganisms like bacteria and molds, which leads to food spoilage and potential illness.
Step-by-step explanation:
The condition in a dry storeroom that can cause food to become unsafe is B. High humidity. High humidity increases the moisture available in the environment, which can encourage the growth of microorganisms such as bacteria and molds. These microorganisms are hazardous as they can lead to food spoilage and foodborne illnesses. Foods like jams and dried meats often do not require refrigeration as the removal of water through drying or the addition of sugar in jams reduces water activity (aw), which is necessary for bacterial growth. The refrigeration and ventilation in storage facilities for fruits and vegetables help maintain low temperatures and adequate airflow, preventing the rapid multiplication of microorganisms, which thrive in the temperature danger zone between 4°C and 60°C (40°F and 140°F).