The provided architectural plans contain the specific dimension for the guardrail height. On Sheet A10, Detail 1, titled "RAMP/STAIR GUARDRAIL," a dimension line clearly indicates the height from the "T.O. CONC." (Top of Concrete) walking surface to the top of the guardrail. This dimension is explicitly labeled as "3'-6"", which is 3 feet 6 inches. This height is a standard requirement for guards intended to prevent falls from elevated surfaces like ramps and stair landings.

A. 1 ft 3 in (38 m): This dimension is not shown for the guardrail on the provided plans and is far too low to serve as effective fall protection.

B. 1 ft 7 m (48 m): This dimension is not indicated on the plans for the guardrail and is an insufficient height for safety purposes.

C. 2 ft 10 in (86 m): This dimension, while shown in the detail, represents the height of the handrail, not the top of the overall guardrail structure.

1. NFPA 101®, Life Safety Code®, 2021 Edition. Chapter 7, Means of Egress, Section 7.2.2.4.5.2 states, "The height of guards required by 7.2.2.4.1 shall be measured from the walking surface to the top of the guard and shall be not less than 42 in. (107 cm)." The dimension 3 ft 6 in is equivalent to 42 inches, confirming the plan's adherence to this standard.

2. Ching, F. D. K. (2014). Building Codes Illustrated: A Guide to Understanding the 2012 International Building Code. John Wiley & Sons. Chapter 10, Means of Egress, Section 1013.3, "Guard Height," illustrates and specifies that required guards shall not be less than 42 inches high. This is a standard academic and professional reference confirming the code requirement reflected in the plans. (Note: While this references the IBC, its requirements for guardrail height are harmonized with NFPA 101 for this application).