Doubt in question TC

Newborn babies are perfectly (i) _____________ , as yet unable to be concerned for others, or even to understand a difference between themselves and the world around them. As young children mature, they make the (ii) ______________ discovery that other people exist and have their own needs and desires— in other words, that the entire world is not about them.
A) solipsistic
B) sophomoric
C) quixotic

in this question for solving first blank we should consider idea after yet or “concerned for others”.

the idea is as yet unable to concerned for others : \underline{Rephrasing:}"they are not able to concern about other yet " thus, they’re selfish(Guess for blank(i))

thanks!!