In this one-word substitution question, choose the single English word that best expresses the idea "combustibles – flammable", that is, something capable of catching fire and burning easily.

Introduction / Context:
This question tests your understanding of a descriptive adjective used for fire-related situations. The phrase "combustibles – flammable" indicates materials that can catch fire and burn readily. Many technical and safety documents use specific adjectives to warn about the fire risk of substances, and recognising such words is important in science, engineering, and general awareness contexts.

Given Data / Assumptions:
The phrase indicates that we are talking about things that can burn easily. We must select the adjective that describes such flammable or burning material. We assume standard English meanings and no special grammatical trick.

Concept / Approach:
The adjective "conflagrant" relates to being on fire or in a state of burning. It is connected to "conflagration", which means a large, destructive fire. Since combustibles are materials that burn and flammable means easily ignited, "conflagrant" best matches this idea. The other options describe grammatical cases, processes of clustering, or calming effects and therefore do not correspond to burning.

Step-by-Step Solution:
Step 1: Focus on the central idea: capacity to catch fire and burn. Step 2: Recall that "conflagrant" and "conflagration" are associated with fire. Step 3: Check if any other option is related to fire; none are. Step 4: Match "conflagrant" with the concept of combustibles and flammability. Step 5: Choose Option B as the correct one-word substitution.

Verification / Alternative check:
To verify, think of phrases such as "a conflagrant mass of debris" or "conflagrant material", which signal things that are burning or easily capable of burning. These align well with the idea of combustibles. If you tried inserting "allative" or "calmative" instead, the result would not make sense in any sentence about fire risk or burning substances, confirming that "conflagrant" is the only viable option.

Why Other Options Are Wrong:
Option A, "Allative", is a term in grammar describing motion toward something; it has nothing to do with combustion. Option C, "Agglomerative", refers to clustering or sticking together, as in particles forming a mass, but does not inherently involve fire. Option D, "Calmative", describes something that calms or soothes, often used with medicine, which is the opposite of the destructive energy suggested by combustibles. Therefore, none of these correctly expresses "combustibles – flammable".

Common Pitfalls:
Because the options all sound technical, many students attempt to guess rather than recall meanings. Some may be tempted by "agglomerative" because combustibles can clump together, but the phrase in the stem clearly emphasises burning, not clustering. To avoid such mistakes, focus on the core concept first, then check which option is genuinely connected to that concept. Building a mental map connecting "conflagrant" with "conflagration" and "fire" is a helpful memory aid.

Final Answer:
The correct answer is "Conflagrant".