Answer:
The first object (black)
Step-by-step explanation:
The thermal radiation of a body is governed by the Stefan Boltzmann Law, which is mathematically given as:
![E=\epsilon. \sigma.T^4](https://img.qammunity.org/2020/formulas/physics/college/lcyghzxoikw51eckjqevtv6rucqfcz4cmn.png)
where:
(Stefan Boltzmann constant)
- Also the absorptivity and emissivity of a perfectly black body is maximum ( =1 ) therefore it absorbs all the heat energy incident on it and glows the brightest due to the perfect emission.
So here also the black object will glow brighter than the others.