The zone of proximal development is the difference between what the learner knows and what the learner is capable of
a. understanding with the from a peer
b. teaching to another less capable peer
c. understanding on one’s own
d. teaching to another more capable peer

a)

Explanation:

The zone of proximal development was a concept that was introduced by Vygotsky and refers to the difference between what one learner can do by himself and what he can do with the help of guidance of another person (peer, caregiver, adult).

Therefore, we can say that the correct answer would be a) understanding with the help from a peer.

Why the other options are not right?

b) is not correct because he cannot teach to another person since this zone refers to what he can do with help.

c) Since he needs other people to achieve his goal, he cannot understand it on his/her own.

d) again, he cannot teach since he/she cannot even do it yet without help.

sounds good to me mate!