The opportunity cost of a chosen activity refers to the value of the next best alternative that is given up. In other words, it is the value of the benefits or opportunities that are forgone or lost as a result of choosing one option over another.

Option 1, out of pocket cost, refers to the actual monetary cost or expenses incurred for a particular activity. While this cost is relevant, it does not capture the full opportunity cost as it does not take into account the value of the alternative opportunities that are forgone.

Option 2, out of pocket cost plus cost incurred by the government, expands on option 1 by including any additional costs borne by the government. However, it still fails to capture the concept of opportunity cost, which is about measuring the value of the next best alternative.

Option 3, value of all opportunities forgone, comes close to the correct answer but lacks specificity. It is important to identify and quantify the value of the specific next best alternative that is given up.

Therefore, option 4, value of the next best alternative that is given up, accurately describes the opportunity cost of a chosen activity as it focuses on the specific alternative that is sacrificed and its value. This option aligns with the concept of opportunity cost, which is about evaluating