165. The figure below shows the position–time graph of two moving objects A and B. For how many seconds is the distance between the two objects less than or equal to 20 meters? [Figure: position-time graph $x(\text{m})$ vs $t(\text{s})$, showing two curves A and B; A starts higher around 200 m, B slightly lower; both curves intersect; graph shows values at 100, 200 on $y$-axis and $-200$ below origin, with $t = 10$ marked on $x$-axis]
[(1)] 8
[(2)] 6
[(3)] 4
[(4)] 2
\textbf{165.} The figure below shows the position–time graph of two moving objects A and B. For how many seconds is the distance between the two objects less than or equal to 20 meters?
\textit{[Figure: position-time graph $x(\text{m})$ vs $t(\text{s})$, showing two curves A and B; A starts higher around 200 m, B slightly lower; both curves intersect; graph shows values at 100, 200 on $y$-axis and $-200$ below origin, with $t = 10$ marked on $x$-axis]}
\begin{itemize}
\item[(1)] 8
\item[(2)] 6
\item[(3)] 4
\item[(4)] 2
\end{itemize}