TASK DEFINITION: In this task you are given a sentence. You must judge whether subject of the main clause is singular or plural. Label the instances as "Singular" or "Plural" based on your judgment.
PROBLEM: " Flight # 408 now loading at gate 4B on the north concourse, " came over the loudspeaker.

SOLUTION: Singular

PROBLEM: The second option was a possibility.

SOLUTION: Singular

PROBLEM: He leaned back in his chair, his crotch angled toward me.

SOLUTION:
Singular