Answer :
The stone will feel warmer than the glass after 20 minutes.
What is Conduction?
This can be defined as a process of heat transfer which involves direct contact between the objects.
The stone and the lamp in contact with each other means heat will be transferred to the stone thereby making it warmer and the reason why option B was chosen as the most appropriate choice.
Read more about Conduction here https://brainly.com/question/893656