Scientists have found that the lifetimes of mRNAs coding for pair-rule regulator

Scientists have found that the lifetimes of mRNAs coding for pair-rule regulatory elements in Drosophila embryos may last only a few minutes. What does this suggest about the overall developmental plan of an animal body?

   Timing of pair-rule sequence determination is not as important as spatial signaling.
    The role of mRNAs is less important than the position of genes in chromosomes.
    Building an animal body requires a sequence of precisely timed steps.
    Homeotic genes have greater impact in forming an embryo than mRNA from pair-rule genes.