Explanation:

- Let's analyze the given passage and the options for blank number 5.

- The passage discusses the benefits of physical exercise and highlights walking as a beneficial form of exercise.

- Walking is praised because it doesn't require special equipment, expenses, or additional commitments.

- For blank number 5, we need a word that fits the structure of "equipment, money, material or ___ of a club."

- Option 1: Correlation

- This doesn't fit the context as it refers to a relationship between variables.

- Option 2: Membership

- Perfectly fits as it implies joining or being affiliated with a club, which walking does not necessitate.

- Correct Answer

- Option 3: Exemption

- This doesn't fit, as exemption refers to being free from an obligation.

- Option 4: Scholarship

- This is unrelated to the context of physical exercise and clubs.