Between birth and one year, infants are dependent on their caregivers; therefore, caregivers who are responsive and sensitive to their infant's needs their baby to develop a sense of the world as a safe, predictable place. what is the primary developmental task of this stage?

I believe the answer is: Trust vs. mistrust
Trust vs. mistrust would refers to a period in infant's development when they're feeling uncertain about the world which they live in.
This often lead to constant paranoia and self defense mechanism everytime they spot an irregularity in their current environment.