I believe that the answer to your question would be A. Heart Begins.
Answer:
Fracking can contaminate water supplies if it is not done properly, because the fracking fluid injected into rock to enable gas to be released often contains chemicals. If the borehole is not properly cased to stop leaks, the fracking water can escape into the aquifer
Answer:
The four organelles that contribute to the synthesis, transport, packaging, and export of proteins to the extracellular environment are Nucleus, RIBOSOMES, rough endoplasmic recticulum and Golgi apparathus.
Explanation:
The nucleus is the organelle that produced RIBOSOMES.
RIBOSOMES are organelles responsible for protein synthesis production of proteins.
The protein produced by the RIBOSOMES are then gathered in the rough endoplasmic recticulum . It then export and transport the protein to Golgi apparatus. The Golgi apparatus modifies and package the protein.

The digestion of protein begins at mouth and it continues at stomach and small intestine.
Hope it helps:)