Read the given passage and answer the questions.

For those of us without access to outside green space, houseplants are a stylish and affordable way of getting a nature fix. Alongside looking nice, indoor plants actually have several other perks - the biggest benefit of which could be improving your mental health. And the good news is you don’t need to be a self-professed “plant parent” to experience these benefits either. One in eight UK households don’t have access to any kind of garden. Young people and those from minority ethnic backgrounds are among those least likely to have a garden. Not having access to nature can have a number of effects on our health. It’s been linked to symptoms of depression and anxiety, as well as other health conditions, such as asthma, cardiovascular disease, and poor immune function. For many of us, houseplants are an essential link to nature. While there’s not yet a robust body of research on the mental health benefits of houseplants specifically, plenty of studies have shown how beneficial green space and gardening are for mental health. For instance, one study found that people who garden daily have better wellbeing and lower stress levels compared to those who don’t. Gardening also reduces symptoms of depression and anxiety and increases positive emotions to the same extent as biking, walking and eating out. Many of these outcomes are likely to be true of houseplants too. A recent review of 42 studies demonstrates that even just being in the presence of indoor plants can improve mental and physical health. These experiments compared participants doing various activities in rooms with or without plants. The presence of plants saw better performances on cognitive tasks involving focus, sorting or memory recall, greater pain tolerance when holding hands in ice cold water, and lower levels of physiological stress. Interestingly, the aesthetic appearance of plants is important too, with separate research showing that people tend to react more positively to lush, green plants with rounded and denser foliage. But most of these studies are centred around the mere presence of plants. From research on the benefits of gardening, we can assume that caring for houseplants will bring out many more emotional benefits - such as pride, social connection, satisfaction, fascination, mental resilience in times of stress, and may even help you heal from past trauma…. Plants can remove pollutants such as carbon dioxide, nitrogen dioxide (from nearby traffic), fine particles (from dust) and volatile organic compounds (from air fresheners, cooking and cleaning). For people indoors for the majority of the day, indoor air quality is hugely important. High concentrations of carbon dioxide can reduce cognitive performance (such as concentration and memory recall) while prolonged exposure to other indoor pollutants can cause long-term health problems - ranging from minor eye or throat irritations to respiratory problems and cancer. But removing a meaningful quantity of indoor pollutants would require a lot of plants in a very bright room - something unrealistic for most people. If you do want to give it a try, plants with a high leaf area - such as an India rubber tree (Ficus elastic) or devil’s ivy (Epipremnum aureum) are your best bet.