A predicate nominative is a word or word group that is in the predicate and that identifies the subject or refers to it. A predicate nominative appears only in a sentence that has a linking verb. Common linking verbs include is, was, will be, has been, and could have been.
It is C.
Volunteer is a predicate nominative.
<em>Hope this helps!</em>
The first-aider will be ready with a first aid kit and will be on guard in case of accidents or injuries. First aid means, the first action done on someone who is injured or not feeling well within the designated place. He/she must know some first aid treatments or methods, such as treating a cut or bruise, giving artificial ventilation and CPR, etc.