National Highways in India — indicative total length range (textbook-era data) Choose the range that best represents the traditionally quoted total length (km) of the National Highways network in India, as used in standard exam references.

Introduction / Context:
Civil engineering competitive exams often use conventional, textbook-era statistics for transport infrastructure. This item asks for the broadly cited range of the total length of National Highways (NH) in India used in such references, not necessarily the current value (which changes over time due to upgrades and reclassification).

Given Data / Assumptions:

• Question targets historically quoted range from standard exam manuals.
• Exact year is not specified; we rely on the traditional range commonly taught.
• Units are kilometres (km).

Concept / Approach:
In many legacy texts and older question banks, the NH network length is typically placed in the band of a few tens of thousands of kilometres, with the most common range cited as 45,000–55,000 km. This reflects the status before subsequent expansions. The task is recognition/recall rather than a calculation.

Step-by-Step Solution:
1) Consider the set of provided ranges.2) Identify the historically prevalent figure (about fifty thousand kilometres).3) Choose the matching option 45,000 to 55,000 km.

Verification / Alternative check:
Cross-check with traditional exam prep books which tend to quote approximately fifty thousand kilometres for NH in legacy data tables.

Why Other Options Are Wrong:
Lower ranges (15–25k, 25–35k, 35–45k) understate the legacy figures; the NH system has long exceeded these bands.

Common Pitfalls:
Confusing present-day network lengths with the historical numbers used in older exam questions; not noting that actual figures evolve over time.

Final Answer:
45,000 to 55,000