Answer : Option B

Explanation :

Here if we consider the universe is consisting of heat engine and corresponding high and low temperature reservoirs and to take the heat from the heat engine an surrounding as the components in the universe, than as the process goes on the temperature of the hot reservoir decreases and at some point the temperature of the universe becomes uniform and no more conversion of heat to work takes place. So, we can say as the spontaneous process is taking place in the universe the entropy is increasing of the universe and the heat engine efficiency is decreasing as the temperature is gradually becoming uniform throughout the universe.