The correct option is B Aestivation
Arrangement of sepals and petals with respect to other is Aestivation. Aestivation or estivation refers to the positional arrangement of the parts of a flower within a flower bud before it has opened. Aestivation is also sometimes referred to as praefoliation or prefoliation, but these terms may also mean vernation: the arrangement of leaves within a vegetative bud.
Therefore, the correct answer is option B.