Answer:

According to blank slate theory, the mind is completely blank at birth. From there, education, environment, and experiences – which are external, as well as material and/or immaterial – shape the child's process of development. This leaves a lasting effect on who they become.
Answer:
D seems the most convincing but i could be wrong.
B.) Garden
this is because "on" is one of many words that are commonly in prepositions. Then to find the object of the preposition, you have to ask yourself, "on {or insert whatever your word is here} what", because the object of your preposition is the subject of the preposition. :)
I hope that makes sense!