Answer: Question 1 is A. C is wrong because without much notice would be informal. B is wrong because posting it on the newspaper it would be visible to everyone even people you don't know.
Question 2 The answer would be B because Madrid is the largest city in Spain. Answer A and C is wrong because both of them are true.
Question 3 the answer is B. Sorry I can't give an explanation I have to go. Let me know if these answers are correct.
Explanation:
Estoy confundido ¿cuál es la pregunta?
What are you asking?
do need translation?
Answer:
isn't it hola nd hello in English