Which of the following set of statements best represents the nature and objective of teaching and learning ?

(a) Teaching is like selling and learning is like buying.
(b) Teaching is a social act while learning is a personal act.
(c) Teaching implies learning whereas learning does not imply teaching.
(d) Teaching is a kind of delivery of knowledge while learning is like receiving it.
(e) Teaching is an interaction and is triadic in nature whereas learning is an active engagement in a subject domain.