The correct answer is A) microorganisms are transmitted from one organism to another.
The chain of infection is a process in which microorganisms are transmitted from one organism to another.
The chain of infection starts with the agent of infection that is the one which makes people sick. It exists in a reservoir, where the agent of infection lives. There is a portal of exit. It is the way the agent leaves the reservoir. Then we have the mode of transition. It could indirect or direct contact with the agent. The agent o infection enters a new body through what is known as a portal on entry. Finally, the host. It is the individual who receives this agent and gets sick.
I believe the answer is C?
<span>When a physical need has been achieved to a drug or alcohol, this is referred to as dependence or addiction. The endocrine system toxicity dependence or addiction motor function issues. Hope this answers the question. Have a nice day.</span>
Smallpox<span> vaccine, the first successful vaccine to be developed, was introduced by Edward Jenner in 1796. He followed up his observation that milkmaids who had previously caught </span>cowpox<span> did not later catch </span>smallpox<span> by showing that inoculated</span>cowpox<span> protected against inoculated </span>smallpox<span>.</span>
