Answer: Option (b) is the correct answer.
Explanation:
An open system is defined as the one where there will occur exchanges of matter as well as heat energy between the system and surrounding.
For example, when a boil water then its heat energy will move into the surrounding and also matter is moving to the surrounding in the form of water vapor or steam.
On the other hand, a system in which there will occur no exchange of matter but exchange of heat will occur from the system to the surrounding is known as a closed system.
For example, coffee placed in a cup covered with lid is a closed system.
Thus, we can conclude that the statement heat and matter are both able to enter or leave the system best expresses the definition of an open system.
