In this sentence, the direct object is "the alarm." It is the noun that receives the action of the verb "set." The subject is "I," which is the person or thing that performs the action of failing to set the alarm. The subject complement is not present in this sentence. It is a word or phrase that follows a linking verb (such as "is" or "was") and renames or describes the subject.
Obviously, something is missing here. What is the question??
