Q28. High levels of demand have decreased the supply of un-allocated internet protocol version 4 addresses available for assignment to internet service providers and end user organization since the _____:

Вариант ответа 1 - a) 1980s

Вариант ответа 2 - b) 1990s

Вариант ответа 3 - c) 2000s

Вариант ответа 4 - d) None of These