Answer: The answer is either Embryonic period or Fetal Stage
Explanation:
The placenta is just a sack that gives nutrients to the baby, germinal and zygotic are within the first few weeks of pregnancy, so nothing much has developed. My guess is the fetal stage.
It acts an insulator on the neurons. The neurons are covered with it and hence the nerve impulses have to jump over the myelin sheath to reach other neurons. This causes nerve impulses to move rapidly from neuron to neuron.
The answer is the Dinosaurs and the Pterosaurs.
The Jurassic Period follows Triassic Period. It is known as the Age of Reptiles. the land was dominated by the dinosaurs and the flying pterosaurs. Both groups are reptiles. Other animals and plants during this period have just recovered from the largest mass extinctions on Earth.
I believe that the MOST reasonable answer would be A.) never use daffodils with other flowers in arrangements. If they are harmful to other plants it would be best to just keep them seperate, and the rest of the other options just seem unreasonable and too much work just for something so simple :P