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: The healers were closely monitoring Branden's condition, and there was one in the reception room of his suite when they arrived.

SOLUTION: Plural

PROBLEM: Ahead he could see two Agents, one on either side of the doors.

SOLUTION: Plural

PROBLEM: A mechanized humanoid, dressed in a long vermilion robe, entered the room with inhuman speed and silence, surprising her.

SOLUTION:
Singular