following indicates the answers to Test Yourself: Relative Clauses
Trick Question! Neither
"that" nor "which" would be correct
Sentence 3: This is not
The patient responded well to this treatment, which was a relief to us.
Remember to watch for "which" clauses
at the end of sentences that do not have a clear reference. This
is known as "witch hunting." Was it the treatment that
was a relief? It is more likely that the response of the patient
to the treatment was a relief.
Because a "which" clause cannot
modify an entire sentence but only a noun in sentence, it would
be better to revise this sentence. Here is one possible revision:
The patient responded well to this treatment; her response was a relief to us.
In the revised example, it is now clear what
exactly was a relief: it was not the treatment but the patient's
response to the treatment. Also see the page "Which
to Sample Paragraph