According to Mary Ainsworth's theory of attachment, when a child uses the mother as a home base and feels comfortable leaving this base to explore their environment. This is considered to be which of the following types of attachment?

The concept of attachment types as outlined by Mary Ainsworth is fundamental in understanding how children develop relationships and emotional bonds with their caregivers. In the scenario described, where a child uses the mother as a home base while feeling comfortable exploring their environment, this reflects the characteristics of a secure attachment.

Children with secure attachment typically feel safe and supported by their caregivers. They are likely to explore new spaces and engage with their surroundings because they know they can return to their caregiver for comfort and reassurance. This exploration indicates a balance between seeking closeness and independence, which is a hallmark of secure attachment. It demonstrates the child’s confidence in their caregiver's availability and responsiveness.

In contrast, other types of attachment, such as avoidant, anxious, or disorganized attachment, involve different dynamics where the child may either avoid interaction with the caregiver, crave excessive closeness, or exhibit confusion and apprehension about the caregiver’s availability. These variations do not include the same sense of security and comfort that a securely attached child experiences while exploring their environment.