Circular Path Radius from Step Counts

Let $l$ be the step count distance between consecutive dustbins. Minimum steps to reach every 2nd dustbin is 800 $\implies 2l \ge 800 \implies l \ge 400$. Maximum steps to reach every 3rd dustbin is 1260 $\implies 3l \le 1260 \implies l \le 420$. So $400 \le l \le 420$.

Total steps around circumference $C = 5l$. $2000 \le C \le 2100$ steps. In meters: $2000 \times 0.77 = 1540$ m to $2100 \times 0.77 = 1617$ m. Circumference $2\pi r \in [1540, 1617]$. $r \in [\frac{1540}{2\pi}, \frac{1617}{2\pi}] = [245.1, 257.35]$ meters. Among the options, 250 metres falls in this range.