Given the task definition and input, reply with output. In this task, you will be presented with a question having multiple possible answers in Portuguese language. And you should choose a most suitable option out of "A", "B", "C", "D", and "E" based on your commonsense knowledge.

Question: Antes dos computadores ou telemóveis, um dicionário era uma ferramenta importante para professores e estudantes no quê? 
 Options: A manual B sala de aula C explicar o significado das palavras D quadro E prateleira

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
B