Answer:
Option C is the correct answer.
Step-by-step explanation:
Refer the figure.
We need to find resultant of two perpendicular vectors, that is the actual velocity.
Velocity of Ronjeev = 12 kilometers per hour
Velocity of River = 5 kilometers per hour
[tex]\texttt{Actual velocity = }\sqrt{\texttt{Velocity of Ronjeev}^2+\texttt{Velocity of River}^2}\\\\\texttt{Actual velocity = }\sqrt{12^2+5^2}=\sqrt{144+25}=\sqrt{169}\\\\\texttt{Actual velocity = }13kmph[/tex]
Option C is the correct answer.