Final answer:
The correct size for a makeup air opening in a closet designed for a clothes dryer is 100 square inches. Following this safety standard is crucial for proper ventilation and preventing risks like overheating or fire.
Step-by-step explanation:
When a closet is designed for the installation of a clothes dryer, a minimum opening of 100 square inches for makeup air shall be provided. The correct option is (A) 100. This provision allows for adequate air for the dryer to operate safely and efficiently, preventing issues such as overheating or potential fire hazards. It's important to adhere to these safety standards to ensure proper ventilation and air circulation for the clothes dryer.