The pseudo-root is not a real prim; it visually represents the stage root in usdview.

Validating at each stage isolates issues and prevents regressions.

It serves as the root of the shared scenegraph for instances

Option A is correct because local opinions are the strongest opinions in USD composition strength ordering.
NVIDIA's Learn OpenUSD strength-ordering guide describes LIVRPS, now also written as LIVERPS with relocates included, as the ordered set of composition operations used to determine which opinions win. The order is strongest to weakest: local , inherits, variant sets, relocates, references, payloads, and specializes.
When debugging an unexpected value, local opinions should be inspected first because a directly authored opinion in the local layer stack can override opinions arriving through other composition arcs. NVIDIA's tracing guidance also highlights how complex composition debugging becomes when many prims, properties, layers, and arcs contribute competing opinions.
Option B is false because specializes arcs are not unoverrideable; they are the weakest fallback-style opinions in the composition order. Option C is false because references are stronger than payloads in LIVRPS
/LIVERPS ordering, so checking payloads before references reverses the standard diagnostic priority. This aligns with Debugging and Troubleshooting # LIVERPS Strength Ordering, Local Opinions, References, Payloads, Specializes, and Composition Diagnostics .

Transformations work on the shared USD domain and can be reused across exporters.