Platinum resistance sensor is to be used to measure temperatures between 0 and 200°C. Given that R₀ = 100.0, R₁₀₀ = 138.50, R₂₀₀ = 175.83Ω, and the temperature coefficient α = 3.91 × 10⁻³/°C, then δ equals:
a. 5.85 × 10⁻⁷/°C²
b. 4.05 × 10⁻⁷/°C²
c. -4.05 × 10⁻⁷/°C²
d. 5.85 × 10⁻⁷/°C²