The answers are C and D.

The sentence suggests that the physical characteristic seen in the remains of soldiers who fought in the fifteenth-century battle of Towton is unsurprising or expected, given the disparate or fundamentally different origins of the men who participated in the battle. The logic involves recognizing a connection between the observed physical characteristic and the diverse or distinct backgrounds of the soldiers.

Blank (i):
A. decay: This term doesn't align with the idea of physical characteristics seen in the remains of soldiers. It suggests a process of deterioration rather than a visible attribute. Therefore, it is not the correct answer.
B. strength: While "strength" could be a physical characteristic, it doesn't convey the sense of variety or differences in the observed remains. It's not the correct answer.
C. diversity: This term fits well with the context of the sentence, suggesting a range of physical characteristics observed in the remains of soldiers. It is the correct answer.

Blank (ii):
D. disparate: This term accurately conveys the idea that the origins of the soldiers were fundamentally different or distinct. It is the correct answer.
E. unknown: While the origins could indeed be unknown, the sentence emphasizes the idea of differences or diversity in the origins. "Unknown" doesn't capture this nuance as well, so it is not the correct answer.
F. controversial: This term doesn't fit the context of the sentence, which is more about recognizing differences in the origins of the soldiers rather than suggesting controversy or disagreement. It is not the correct answer.