Why are PVC (uPVC) doors and windows commonly preferred in residential and commercial projects? (Assess durability against rust, rot, termites, and water exposure.)

Introduction / Context:
PVC/uPVC frames have become a mainstream choice for fenestration owing to their durability in humid, coastal, and termite-prone regions. The question examines the range of environmental resistances that justify this preference in practice.

Given Data / Assumptions:

• uPVC is a non-metallic polymer that does not rust.
• It is not a nutrient source for fungi, so it does not rot like timber.
• It is not susceptible to termite attack.
• Properly fabricated uPVC systems have excellent resistance to rainwater penetration.

Concept / Approach:
Material selection for doors/windows must consider corrosion, biological attack, and moisture. uPVC offers all-round resistance with low maintenance. Therefore, the most inclusive choice that accurately represents its advantages is 'All of these'.

Step-by-Step Solution:

Verification / Alternative check:
Product literature and standards emphasize durability, low maintenance, and weather resistance of uPVC systems across climates.

Why Other Options Are Wrong:

• Any single property alone understates the multi-factor durability benefit of uPVC.

Common Pitfalls:
Confusing water-proof frames with overall window system leakage (usually due to detailing/installation, not frame material); equating rust resistance with total immunity to hardware corrosion (hardware selection still matters).

Final Answer:
All of these