In Animal Development, the Formation of Complex Three-Dimensional Organs Involves

In animal development, the formation of complex three-dimensional organs involves a number of morphogenetic processes. These include
1) localised cell proliferation
2) migration of individual cells to new sites
3) thickening and infolding of epithelial sheets
4) programmed death of localised groups of cells
5) disaggregation of tissues into individual cells.
Which of the following lists these processes, in the order they are likely to begin, during normal embryonic development of a limb bud in mammals or birds?

A) 5, 2, 1, 3, 4
B) 2, 3, 5, 4, 1
C) 3, 1, 5, 2, 4
D) 1, 5, 2, 4, 3
E) 2, 1, 5, 3, 4