Final answer:
Lipogenesis is not a postabsorptive state reaction; it occurs during the absorptive state when the body is converting excess energy into fat for storage.
Step-by-step explanation:
The question asks which of the following is not a postabsorptive state reaction. During the postabsorptive state, the body primarily focuses on providing energy by breaking down stored reserves, such as glycogenolysis (the breakdown of liver glycogen), and gluconeogenesis using lactic acid or amino acids to create new glucose molecules. Therefore, options a), c), and d) are reactions that occur during the postabsorptive state. However, lipogenesis (option b) is the process of synthesizing fats from acetyl CoA, which primarily occurs during the absorptive state, when the body is storing excess energy. So, b) Lipogenesis is the correct choice as it is not a postabsorptive state reaction.