This task is about identifying the subject of a given sentence. The subject of a sentence is the person, place, or thing that is performing the action of the sentence. The subject represents what or whom the sentence is about. Each sentence in this task is guaranteed to contain a single subject. The input is a sentence and the output is the identified subject of that sentence.

The operator of Apollo 12 was NASA.
Apollo 12

Construction of Adisham Hall began in 1927.
Adisham Hall

Joe Biden is the United States leader.

United States