The correct answer is B. A conjugated reflexive verb
Step-by-step explanation:
A reflexive verb is one in which the object is the entity acting or subject. In Spanish, these verbs can be identified because in their infinitive form they end in "se", for example in "preparase" (prepare oneself) or in "vestirse" (dress one-self). Moreover, once these verbs are conjugated the words "me", "se", "te", "nos" are used before the verb to indicate the noun that is receiving the action (object). In the case of "me quedo" (I stay), this is a reflexive noun because the action "quedarse" has as a direct object the noun "I". Also, this is conjugated and you can identify this because the verb is preceded by the word "me".