The answer is D because its basically DNA
The answer should be 1.
Photosynthesis only occur when leaves are formed,
When is seed is produced, they already have a lot of nutrients inside stored until they grow leave to undergo photosynthesis.
Pulmonary vein brings oxygenated blood to the heart from the lungs
Pulmonary artery take deoxygenated blood to the lungs
I would go with B. Because they are the most used.