1. Logical Walkthrough

The passage makes three sequential claims, each one carefully qualified:
- Claim 1: By the fourteenth century, the capacity to use restricted written Latin was nearly universal in English communities - the key word is "capacity," meaning active deployment, not passive exposure
- Claim 2 (concessive qualification): It would be naive/unrealistic to assume every provincial business writer drew on the full richness of Latin literature since 1100
- Claim 3 (partial restoration): But even humble schoolbooks transmitted some classical elements - meaning the claim in Claim 1 is reinforced: Latin literacy, though limited, was genuinely widespread

The final sentence - "Latin literacy was not, in these circumstances, exclusive" - is the logical anchor. It tells you the whole passage is building toward the idea that Latin was broadly accessible, not confined to an elite. This drives all three blanks.
2. Blank-by-Blank Justification

Blank (i) - C. deploy:
The sentence says communities had the capacity to ______ Latin. The word must mean to actively use or put into practice. "Deploy" - meaning to put a resource to effective use - is the only verb that logically completes this: you deploy a skill or tool, which is precisely what limited Latin literacy amounts to. "Curtail" (to reduce) and "forgo" (to abstain from) both work against the passage's argument that Latin was available and used.

Blank (ii) - D. fanciful:
The phrase "It would be ______ to suppose" introduces a concessive qualification - the author is pulling back from an overly strong claim. The blank needs an adjective meaning unrealistically optimistic or naively imaginative. "Fanciful" fits exactly: it signals that the supposition being described goes beyond what evidence supports. "Sobering" implies the thought is serious and chastening - opposite in emotional register. "Fortuitous" means happening by lucky chance, which is entirely unrelated to the logical act of supposing.

Blank (iii) - H. purveyed:
"Even schoolbooks _______ some elements of classical education" requires a verb meaning transmitted, supplied, or made available. "Purveyed" - meaning provided or disseminated - is the precise fit: schoolbooks were vehicles for passing on classical content, however modestly. "Expunged" means erased, which directly contradicts the passage's restorative logic. "Incriminated" means implicated in wrongdoing, which is semantically absurd in context.