Participants were asked to indicate which of the following mediums they plan to use to advertise their products or services.
which of 뒤로부터 해석은 얼추되는데 문장분석이 안되요..
which of 가 의문사라면
which of (의문사) / the following mediums (주어) / (목적격 관계대명사 생략) they plan to use to advertise / their products or services(????)
이렇게 생각해도 뒤에 their부터 이상하고...
깔끔한 설명쫌 부탁드려요~~