Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 18 to 24 .

Online social media have gained amazing worldwide growth and popularity. Although with time a generations have come to accept the changes social networking including Twitter, Facebook or Instagram has brought about, teenagers and young adults are the most frequent users of these sites. It has been reported that these sites are affecting the lives of the youth greatly. Social media sites have provided a platform whereby the youth can create groups and pages based on their common discipline and end up building connections and opportunities for their respective careers by updating various topics to discuss. Youth who have been interviewed they say that social media has become their lifestyle and it makes their lives easier and efficient.

Social network sites seem to bring people together and connected, but may create social isolation. As the youth tend to spend many hours on these sites, they rarely have face-to-face interaction. According to various studies, scientists' evaluation determined that social isolation can lead to a host of emotional, psychological, physical and mental problems which include anxiety, depression and somatic complaints among many others. Other negative effects of social networking various people suggested included encouraging poor spelling and grammar, allowing spread of misinformation that is perceived as fact. decreasing productivity. The sites also provide a perfect platform for cyber bullying and increase risks of identity theft, whose personal information are asked to add. Social networking clearly portrays both positive and negative effects on the youth. It is decision of an individual to make whether to continue using the sites or not

Which is the closest in meaning to the phrase "social isolation" in paragraph 3?