In which sentence does the noun phrase " a high-pitched screech" act as the subject? a. a crow's call, a high-pitched screech, startled the family. b. we heard a high-pitched screech , a crow's call, a few minutes ago. c. the crow's call is sometimes a high-pitched screech. d. suddenly, a high-pitched screech, the crow's call, pierced the air.

The sentence in which the noun phrase " a high-pitched screech" act as the subject is D. Suddenly, a high-pitched screech, the crow's call, pierced the air. All these sentences are quite complex and contain subject, predicate and object. In the first sentence it acts like an object because the action is performed by 'crow's call'. The doer of the second sentence is 'we' and in option C this phrase stands as an object which brings additional sense to the subject ;crow's call;. In this way, the correct answer is D, and the ;crow's call; is the object.