The number of deaths among the army personnel is 8 in 1000, but among the civilian population it is 20 per 1000. Which one of the following inferences can be drawn from this statement?

The two groups of army personnel and civilians respectively, are completely unrelated. Both groups are subject to different probable causes of death. For example, army personnel are subjected to the risk of death while fighting in a war, while this is something that a civilian may not necessarily be exposed to. Similarly, a civilian may die of starvation due to poverty; this is something that may not happen in the army. Therefore, the two groups are heterogeneous and cannot be compared. Option (d) is correct.

Option (a) is incorrect, because joining the army does not preclude death.

Option (b) is incorrect, because it is unclear which relationship is being referred to as fortuitous here- the relationship between the two groups or the relationship between death and each group respectively.

Option (c) is incorrect, because we have no data regarding the quality of life within the armed forces.

Hence, the correct answer is option d.