Trypanosomes (Trypanosoma brucei) are protozoans that cause African sleeping sickness in humans. The diagram shows the way that the disease is transmitted to humans.
 

Which row of the table identifies the pathogen, vector and method of disease transmission to humans?

\begin{align*}
\begin{array}{l}
\ & \\
\ & \\
\textbf{A.}\\
\textbf{B.}\\
\textbf{C.}\\
\textbf{D.}\\
\end{array}
\begin{array}{|l|l|l|}
\hline
\ \ \textit{Pathogen} & \ \ \textit{Vector} & \ \ \textit{Method of disease} \\
\textit{} & \textit{} & \ \ \textit{transmission} \\
\hline
\ \ \text{Trypanosomes}\ \  & \ \ \text{Tsetse fly}\ \  & \ \ \text{Direct} \\
\hline
\ \ \text{Tsetse fly} & \ \ \text{Cow} & \ \ \text{Direct} \\
\hline
\ \ \text{Trypanosomes} & \ \ \text{Tsetse fly} & \ \ \text{Indirect}\ \ \\
\hline
\ \ \text{Tsetse fly} & \ \ \text{Cow} & \ \ \text{Indirect} \\
\hline
\end{array}
\end{align*}