토익 고난도 문법(17) 'When'의 축약

Employees of Skyhigh Industries offered helpful suggestions _______ interviewed by a consultant from Baker Business Solutions.

(A) when

(B) are

(C) this

(D) from

* when S + V, 즉, when 다음엔 주어 동사가 나와야 하지만, 'S + V'가 생략된 형태.