Lane and Garton proposed a way to classify crude oils/petroleum streams. Their classification is primarily based on which fundamental aspect among composition, specific gravity, optical properties, or viscosity?

Introduction / Context:
Crude oil classification systems help predict behavior during processing and product quality. Lane and Garton’s approach focuses on the hydrocarbon family make-up of the petroleum material rather than a single physical property like density or viscosity.

Given Data / Assumptions:

• Classification aims to indicate predominant hydrocarbon types.
• Options include bulk properties and compositional focus.
• Used historically for refinery planning and product expectations.

Concept / Approach:
Composition-based schemes distinguish paraffinic, naphthenic, and aromatic bases, which strongly influence yields and product qualities (e.g., wax content, smoke point, solvency). While properties like specific gravity correlate with composition, Lane and Garton emphasize the actual hydrocarbon family distribution—the compositional fingerprint.

Step-by-Step Solution:

Verification / Alternative check:
Refinery literature associates Lane–Garton with paraffinic/naphthenic/aromatic descriptors rather than pure density or viscosity classes.

Why Other Options Are Wrong:

Common Pitfalls:
Equating API gravity with composition; many crude families overlap in density ranges.

Final Answer:
Composition