Studies Have Shown That in the Flowering Plant Arabidopsis the Development

Studies have shown that in the flowering plant Arabidopsis the development of parts of a flower is governed by ____.

A) differential uptake of hormone signals from the leaves
B) the oxygen gradient from outside to inside of the closed flower
C) differentiation of cell types as they are formed from the apical meristem
D) the timing of cell division
E) the expression patterns of several floral organ homeotic genes