Select the option that expresses the given sentence in passive voice.
Nandita was seeking a good research area where she could prepare a good proposal for submission.

A good research area was sought by Nandita where a good proposal could have prepared by her for submission.

A good research area was being sought by Nandita where a good proposal could be prepared by her for submission.

A good research area were sought by Nandita where a good proposal could prepare by her for submission.

A good research area had been sought by Nandita where a good proposal could have been prepared by her for submission.