Explanation:

- Assertion (A): Fatty acids should be a part of the balanced human diet.

- This statement is true. Fatty acids are essential for various body functions and must be included in the diet.

- Reason (R): The cells of the human body cannot synthesize any fatty acids.

- This statement is false. The human body can synthesize some fatty acids, but not essential fatty acids like omega-3 and omega-6, which must be obtained from the diet.

- Option 1: Both A and R are individually true and R is the correct explanation of A.

- Incorrect. R is not true.

- Option 2: Both A and R are individually true and R is not the correct explanation of A.

- Incorrect. R is not true.

- Option 3: A is true but R is false.

- This is the correct option.

- Option 4: A is false but R is true.

- Incorrect. A is true, and R is false.

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