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.