Answers in bold and underlined.
Answer: Mi materia preferida es el taller mecánico porque me gustan los carros.
Translation: My favorite subject is the mechanical workshop because I like cars.
Step-by-step explanation:
The best option is "preferida". "Tarde" and "despues" are meaningless in this context, since they are not talking about the order in which matters occur during the day. "First" is also not appropriate, since Raúl is not saying that the auto shop is the first subject of his school schedule. "Preferred" means that it is the subject that Raúl likes the most or the one that he enjoys the most.