While the main idea is usually in the first sentence, the next most common placement is in the last sentence of a paragraph. The author gives supporting information first and then makes the point in the last sentence. Here's a paragraph we can use as an example. Try to locate the topic and the main idea.
The last option is correct I’m pretty sure
The three fundamental rights mentioned in the Declaration of Independence that were bestowed upon people by birth are Life, Liberty, and the Pursuit of Happiness.
The tone is dark but is contradicted by how the government always portrays war as something to be proud of when in reality it’s just men who will never return to their families. It tells how wives, mothers, and children weep after learning a loved one has been lost in the field while also glorifying death