Answer: The correct answer is "Esa señora es la esposa de Mauricio".
Explanation: "Esa señora es la esposa de Mauricio" is the correct option because it is the only one that uses a "sustantivo femenino" (feminine noun) to define the head of the subject "señora", which refers to a woman. The Spanish word "esposa" means "wife". In contrast, "padre", "suegro" and "nieto" are masculine nouns since they mean "father", "father-in-law" and "grandson" respectively.