part D
a. A simple reflex agent is perfectly rational if the area that it is operating on at present is the only area where it needs to work i.e if the square in which the robot is standing is the only square dirty then it is rational.Or,if the dirt in the squares are binary and there are only 2 squares where the bot has to move.
It is also perfectly rational if it knows the whole area in terms the work that has to be done.Here,it should know the dirt in all the squares.Then it can move accordingly.

b. If the next state of the environment is completely determined by the current state and the action executed by the agent,then the environment is called deterministic.The greedy robot in part B is almost deterministic except when it has a choice between two squares with same dirt value.In this case it can be programmed to operate differently by different users.So,it may not follow the same path all the time.

c.In an environment where the surface is completely clean in some part of the room and all the dirt is accumalated in a small space at some distance.If the robot starts form the clean part then it will perform very poorly.

d.If the readings are inaccurate then the robot will not be able to detect the real dirt level,consequently it may land up cleaning not so dirty squares and leaving the dirty ones.In all its rationality will reduce,cleaning will be ineffective and slow.

e.The robot here is programmed to go to new squares at present but even if the cleaned square can get dirt again the rationality and deterministic nature of the bot will not be affected.It will take more time to clean the room because of the increase in dirt.