The correct answer is: "trust vs mistrust"
The question is refered to Erickson's steps of psychosocial development. This theory appoints that each stage in life poses a challenge. Two opposing forces act over the person, who has to be able to resolve the trade-off, by adopting the positive force (trust in this case) and discarding the negative one (mistrust), in order to sucessfully advance in the development of his/her psychosocial personality. The sucessful resolution of one step enables to arrive to the next step.
In this period, between birth and one year old, the first step, trust vs mistrust, would be operating. The main characteristic of this step is the great uncertainty with which the child perceives the world in which he/she lives.