Regarding runway threshold markings used to identify the threshold location and approach end, which of the following specifications correctly describe standard practice?

Introduction / Context:
Threshold markings are longitudinal stripes placed at the approach end to identify the beginning of the runway available for landing. Their number, spacing, and dimensions provide clear visual cues to pilots on final approach and are standardized to promote uniformity and recognition across aerodromes.

Given Data / Assumptions:

• We are considering the pattern, dimensions, and placement of threshold stripes.
• The options list stripe width, clear spacing, stripe length, and symmetry about the center line.

Concept / Approach:
Classic exam references in Indian syllabi provide indicative values for stripe width (around 4 m), clear gaps (about 1 m), stripe length (around 45 m), and require symmetric arrangement about the runway center line. While real-world standards (e.g., ICAO Annex 14) tie stripe number/dimensions to runway width and category, these listed figures are accepted conventional values in many questions.

Step-by-Step Solution:
Confirm that width, spacing, and length values match the conventional figures.Note that alignment is symmetric about the runway center line.Therefore, all listed statements are collectively correct.

Verification / Alternative check:
Many training manuals present these exact figures for calculation-free recall; detailed standards may differ slightly, but the exam expects the “all of the above” grouping.

Why Other Options Are Wrong:

• Any single statement alone is incomplete; the comprehensive choice reflects the full specification set.

Common Pitfalls:
Mixing up touchdown zone markings with threshold markings; forgetting symmetry about the center line.

Final Answer:
All of the above