The right answer is the A: Raúl, Rafael and Federico, fellow poets and close friends who had lived with him in the emblematic House of the Flowers in Madrid, and who were indeed like brothers to him. He remembers them in these lines with nostalgia and affection. They were the Argentinian Raúl González Tuñón, and the Spaniards Rafael Alberti and Federico García Lorca, whose assassination at the beginning of the Spanish Civil War (1936) caused a tremendous impact on Neruda and on his poetry.