The fastest distribution of some injectable material/medicine with no risk of any kind can be achieved by injecting it into the

Explanation:
The fastest distribution of injectable materials with no risk of any kind can be achieved by injecting the material into veins intravenously.
Intravenous drugs are the fastest route for the distribution of drugs to their target.
The chances of any risk are quite low in intravenous injection. So, veins are the correct answer.
(A) option is incorrect as lymph already contains immune cells that’s why there is no need to inject the drugs into lymph vessels.
(B) option is also incorrect as it produces a local effect.
(C) option is also incorrect arteries are located deep inside the body and hence proper surgery to inject anything onto them.
Final Answer:

Hence, the correct answer is (D) Veins.