According to the above graph, which of the following descriptions of the labour force in Hong Kong from March 1990 to September 1995 is correct?
A. In terms of employment, the manufacturing sector was declining while the service sector was growing.
B. The output per employee in the manufacturing sector was falling.
C. One major source of manpower in the service sector was imported labour, including domestic servants.
D. The real wage of the service sector was increasing.