Which of the following is considered a soft spot on an infant’s skull?

The correct answer is the fontanel, which refers to the soft spots on an infant's skull. These areas are made of flexible tissue that allows for the expansion of the skull during brain growth and facilitates the delivery process during childbirth.

Fontanels are crucial for accommodating the rapid growth of the brain in the first few years of life. They typically close as the child matures, with the anterior fontanel usually closing around 18 to 24 months of age and the posterior fontanel closing earlier, around 2 to 3 months.

The other options, such as suture, mandible, and frontal bone, do not describe soft spots. Sutures are the joints between the skull bones but are not considered "soft spots" since they are harder and more rigid structures. The mandible is the lower jawbone and does not pertain to the soft areas of an infant's skull. The frontal bone is one of the cranial bones forming the forehead, and while it may be involved in the overall structure, it does not represent the flexible areas that are termed fontanels.