Ella ______________ enferma.
Answer: D.) se siente
Entire sentence: Ella se siente enferma.
Translation: She feels sick.
Explanation: "Sentirse" is a reflexive verb, as the subject in this sentence is "Ella", that is third-person in the singular, the reflexive pronoun must have this form: "se", which can mean "a él, a ella, a ellos, a ellas, a usted, a ustedes"