According to ainsworth's research using the strange situation procedure, infants used the mother as a safe base from which to explore the environment. a. securely attached b. anxious/ambivalent c. maternally based d. nonagoraphobic

Answer is a. securely attached.

An infant who is securely attached to its mother is confident enough to explore and play freely in an unfamiliar environment in the presence of the caregiver is present. When the caregiver is present, infant uses her as a "safe base". Only in presence of caregiver infant engages with the stranger and becomes upset in absence of the caregiver. On return of caregiver the child become happy again.

it will increase due to the time span

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands