By citing the toothpaste is out of the tube, the author intends to mean that______.
A.
a younger generation of unskilled immigrants has been produced and their number will grow
B.
the unskilled immigrants have dragged down the wages of the natives and will continue to do so
C.
the children of unskilled immigrants have done poorly in school and will likely to drop out soon
D.
the unskilled immigrants have already been here and will certainly not return