Read the following passage and solve the questions based on it.
There are five rooms in my house in Patna—a hall, kitchen, study room, bedroom and dining room. There is one light in each room. The following clever arrangements are planned in the house:
(i) Whenever the kitchen light is ‘on’, the study room light is ‘off’.
(ii) Whenever the dining room light is ‘on’, the kitchen light is also ‘on’.
(iii) Whenever the study room light is ‘on’, the hall light has to be ‘on’.
How many lights, at the most, can be ‘on’ simultaneously?