Final answer:
Without additional context or information from the source material, it's impossible to provide the correct duration of Sergio's grandmother's search for her daughter. The accurate answer would normally be located within the text or narrative that the question is based on. Option C is the correct answer.
Step-by-step explanation:
The duration for which Sergio's grandmother had been searching for her daughter is not mentioned in the question itself. It would require additional context or information from a specific text, story, or case study that is being referred to in the question. However, assuming this is a comprehension question based on a given text, the answer would typically be found within that text. In such cases, it is critical to carefully read the provided material to find the correct answer.
Without the relevant source material or context, it is not possible to answer this question accurately. If you have access to the text that this question refers to, please review it and look for any mention of the time frame of the search. If this information is not available, you might need to reach out to your teacher or seek clarification on where the answer can be found.
All the options provided, including 20 years (B), 30 years (C), 40 years (D), and 50 years (E), suggest significant periods that could have had profound effects on the characters involved and the narrative as a whole. The search over such extended periods of time often indicates deep emotional narratives and the impacts of long-term separation.