The correct answer is A.
A faithful officer is always vigilant towards his duties. This means that he is always alert and attentive to his responsibilities. He is not innocent, ignorant, irresponsible, or careless.
An innocent person is one who is not guilty of a crime. An ignorant person is one who does not know something. An irresponsible person is one who does not take their responsibilities seriously. A careless person is one who
does not pay attention to detail.A faithful officer is the opposite of all of these things. He is someone who is trustworthy and reliable. He is someone who takes his responsibilities seriously and does his job well. He is someone who is always alert and attentive to his duties.