The anchorage value of a standard hook of a reinforcement bar refers to the amount of force that can be resisted by the hook without the bar slipping out. The anchorage value is influenced by various factors such as the diameter of the reinforcement bar.

The correct answer to this question is option 'D' - 16D.

Explanation:
The anchorage value of a standard hook is calculated based on the length of the hook and the diameter of the reinforcement bar. According to the Indian Standard Code IS 456:2000, the anchorage value of a standard hook is given by the formula:

Anchorage value = 16D

where D represents the diameter of the reinforcement bar.

This formula indicates that the anchorage value is directly proportional to the diameter of the reinforcement bar. In other words, as the diameter of the bar increases, the anchorage value also increases. This is because a larger diameter bar provides more surface area for the hook to grip onto, resulting in a stronger anchorage.

The factor of 16 is determined based on experimental and empirical studies. It represents the average value of anchorage provided by a standard hook for reinforcement bars of different diameters.

So, the correct answer to the question is option 'D' - 16D, as per the formula provided by the Indian Standard Code.

In conclusion, the anchorage value of a standard hook of a reinforcement bar is given by the formula 16D, where D represents the diameter of the reinforcement bar. This formula indicates that the anchorage value is directly proportional to the diameter of the bar.