Correct Answers:
Blank (i): A. exacting
Blank (ii): D. heterogeneity


Explanation

Blank (i):
The task is to catalogue ritual life across "more than three hundred distinct communities," each with its own customs, dialect, and calendar. This makes the undertaking exceptionally demanding and difficult.

Exacting means making great demands on one's skill, attention, or resources-perfectly capturing the monumental effort required.


Blank (ii):
The word "sheer" signals that the quality of the communities is the source of the difficulty. The communities are not just numerous; they are each "distinct."

Heterogeneity means diversity or variety, which directly matches the description of distinct traditions, dialects, and ceremonial calendars.

Why the others are wrong:
B. perilous - means dangerous. There is no mention of physical risk or danger in the passage.
C. straightforward - means easy or simple, which is the opposite of what the sentence conveys.
E. uniformity - means sameness, contradicting the phrase "no single set of customs could be regarded as representative."
F. paucity - means scarcity or small number, which contradicts "more than three hundred."