A、Carrying out reading activities. B、Comparing newspaper remarks. C、Finding information in a book. D、Answering written questions

About 1 in 20 adults in the United States cannot read English. A new federal study shows that adults made little progress in their reading skills between 1992 and 2003. The National Assessment of Adult Literacy is the most important test of bow well adult Americans can read. Researchers tested 19,000 people over the age of 16. The study represents an adult population of 222 million.
Those who took part were tested on bow well they could read and understand information used in everyday life. The study found that 11 million adults, or 5 percent, cannot read English. They could not answer even the easiest written questions. 4 million of than most likely cannot speak English either. The study shows that more than 40 percent of adults can perform only simple reading activities. For many, even that can ha difficult. 56 percent of adults can perform moderate or complex activities. Moderate can mean finding information in a book. Of that number, 13 percent can perform complex tasks like comparing two different newspaper comments. Researchers say part of the problem is that many young Americans do not read as much for pleasure anymore. Also, than are greater numbers of non-English speaking immigrants. Yet, compared to the last study in 1992, adult reading skills were about the same or lower across every level of education. This was true even among people who have completed college. The Department of Education says the literacy findings show the need for reforms especially at the high school level.
How many people were tested in the study?

What kind of activity is defined as complex activity?