Answer:
Queen Gertrude meets Ophelia, who is singing sad songs and speaking strangely. When Claudius joins them he tells Horatio to watch her and declares 'this is the poison of deep grief: it springs / All from her father's death.
C
you don't need to know how I know.
A reader can found the main idea of a passage by analyzing the connotation of the words, summarize the passage and entering details into a graphic organizer. Analyzing the meaning of each word in the text and summarizing is very important in understanding what message it conveys. Also, using a graphic organizer would lead you to finding the main idea of the passage as it highlights the important parts of the text.