Which part/s of the given sentence has/have an error ? I ordered to h…

The correct answer is Option (1) → (A)

"Order" + object + to-infinitive:

• The verb order takes the person directly as its object, without "to": order him, order the students.
• Pattern: order + person + to + verb.

(A) I ordered to — Incorrect.

• The extra "to" after "ordered" must go.
  Example: The officer ordered the soldiers to march.
• Correct form: I ordered him to leave the classroom.

(B) him to — Correct.

• Him is the object and to begins the infinitive "to leave".

(C) leave the classroom. — Correct.