The Gross National Product (GNP) of USA between 1940 to 1945 more than doubled .
The GNP rose from $91 billion in 1939,to $105 billion in 1940 to $126 billion in 1941,to 193 billion in 1943, to $214 in 1945 .
Now if see the GNP jump from 1940 to 1944 is from $105 billion to $214 billion which is more than double.
The answer is: pseudostratified ciliated columnar epithelial cells.
We can find these type of cells in the upper part of the trachea and bronchi, and through the whole upper respiratory tract (nasal cavity included).
Their job is to produce a mocous secretion (look up <em>cilia</em>) help us to stop external, microscopical, materials from entering our lungs, and so we can sneeze and cough them away.
The answer is A just took that
