''Large AC rooms are found to contain 700 parts per million (PPM) of carbon dioxide as compared to open areas which have only 320 ppm.''---A survey report Conclusions : I. Indoor plants can help reduce the carbon dioxide level in AC rooms. II. Over a period of time, especially during the latter half of one's stay at the workplace, the percentage of oxygen comes down as 85 per cent of the same air gets circulated inside the room.

• if only conclusion I follows
• if only conclusion II follows
• if either I or II follows
• if neither I nor II follows, and