**The Minimum Thickness of a Reinforced Concrete Wall**

When designing a reinforced concrete wall, the minimum thickness is determined by several factors, including structural requirements, load considerations, and code specifications. The appropriate thickness ensures the wall's stability, strength, and durability. Let's explore the options provided and determine the correct minimum thickness.

**a) 7.5cm**

A thickness of 7.5cm (or 75mm) is quite thin for a reinforced concrete wall. Such a thin wall would not provide adequate strength to resist structural loads and external forces. It would be prone to cracking, reduced durability, and insufficient structural stability. Therefore, 7.5cm would not be an appropriate minimum thickness for a reinforced concrete wall.

**b) 10cm**

A thickness of 10cm (or 100mm) is a more common minimum thickness for reinforced concrete walls. This thickness provides better structural stability and strength compared to the previous option. It can withstand moderate loads and external forces, making it suitable for non-load-bearing walls or walls with minimal loads. However, for walls subjected to heavier loads or requiring additional strength, a greater thickness may be necessary.

**c) 15cm**

A thickness of 15cm (or 150mm) is a commonly recommended minimum thickness for reinforced concrete walls. This thickness provides improved structural stability, strength, and durability compared to thinner options. It can withstand higher loads and external forces, making it suitable for most applications. However, specific design requirements and load calculations should be considered to ensure the wall adequately supports the intended loads and functions.

**d) 12.5cm**

A thickness of 12.5cm (or 125mm) falls between the options of 10cm and 15cm. It provides a compromise between the two thicknesses, offering reasonable structural stability and strength. However, it may not be sufficient for walls subjected to heavier loads or requiring enhanced durability. Therefore, it may be suitable for non-load-bearing walls or walls supporting light loads, but not for all applications.

**Conclusion**

Based on the options provided, the most appropriate minimum thickness for a reinforced concrete wall would be **c) 15cm**. This thickness ensures adequate structural stability, strength, and durability for most applications. However, it is essential to consult local building codes and consider specific design requirements and load calculations to determine the precise thickness needed for a particular project.

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