Final answer:
The correct answer is C. estoy. In Spanish, the verb estar is used to express temporary states or conditions.
Step-by-step explanation:
The correct answer is C. estoy.
In Spanish, the verb estar is used to express temporary states or conditions, such as being tired or being happy. In this sentence, the subject 'yo' (meaning 'I') is describing their temporary state, so the correct verb to use is 'estoy'.
Learn more about Spanish verb conjugation