Me answer warning! only if ur good in english don't choose #3 ( it's most likely incorrect) ( i think it might be #1) explain

As I understand a thesis statement, the choice is between 2 and 4. I think by the narrowest of margins, you have to pick 2. But do not be surprised if it is 4. Twain says that he will talk about one of the ways to tell a story, the humorous story. That comes from one. The problem is that he wanders around talking about wit (French) and Comic (British). But when he gets around it, most of the information is in either 2 or 4 and both indicate a direction. Four looks more like a transition statement. Many of these questions that you have posted are so difficult because you don't know how things develop beyond the quotation. Four contains details of where he is going, but the real meat of direction is in two.

2: Answer <<<<<

the unsaturated fatty acid is a fat consist of one or more double bond in the fatty acid chain. if it contains one double bond then called as monounsaturated fatty acid however if, it contains more than one bonds called as a polyunsaturated fatty acid. true fatty acids are called unsaturated fatty acids as it reduces the risk of high blood cholesterol and good for health.

even though there may be variations in human emotions over time, the poem “ a contribution to statistics” by wislawa symborska suggests that the only unchangeable characteristic is mortality.

the author poses a distinction between the approximate and non-approximate numbers which correspond to our need for certainty in life and the difficulty of achieving it. our efforts to measure the exact often fail because the world is not always clearly structured .the poem seems to imply   that the only thing that is certain and has an exact number is death.