Refer to the partial survey plan below $($n$.$t$.$s$.).$ To accurately locate the $25800$ contour

line using interpolation, what is the unknown horizontal distance for $"$d$1"?$ All the

existing spot elevations at the surveyor's grid intersections are stated in millimetres.

The grids are spaced $6$ m apart in both directions. Final answers are rounded to the

nearest millimetre.

$2935$ mm

$3140$ mm

$3375$ mm

Refer to the partial survey plan below $($n$.$t$.$s$.).$ To accurately locate the $25800$ contour

line using interpolation, what is the unknown horizontal distance for $"$d$1"?$ All the

existing spot elevations at the surveyor's grid intersections are stated in millimetres.

The grids are spaced $6$ m apart in both directions. Final answers are rounded to the

nearest millimetre.

$2935$ mm

$3140$ mm

$3375$ mm