13. Consider identical lumps of solid iron taken out of two blast furnaces at different but very high temperatures. The hotter of the two bodies: A. gives off somewhat more red light but much more blue light than the cooler body B. gives off less red light but more blue light than the cooler body C. gives off more light at all wavelengths, but with exactly the same colour distribution as the cooler body D. will have an emission-line spectrum while the cooler body has an absorption-line spectrum