B-first neutral own job · paper

Whole supplied source

Fictional paper scene: First costume-label scene. There are 4 columns A to D, left to right, and 4 rows 1 to 4, top to bottom. All cells have the same size. Up/down mean towards the top/bottom of this page; left/right across this page. One move reaches one neighbouring cell, never a diagonal. Start: B2. Target: D3. The name-card is at A1; the spare-card is at D4. Closed cells: C2. Do not enter or pass through them. Proposed instruction: 2 cells right, then 1 cell down. A supplied helper says: “Reaching D3 would make the whole proposed route legal.” This is a supplied scene. Read its whole legend before the questions; it is not a real place, a measured route or an observed journey.

Name or mark the supplied start and target positions.

Which first attempted one-cell move in the proposed instruction would enter a closed cell? Name that cell.

Give a complete legal route from the supplied start to the target that avoids the closed cell.

Does the supplied helper claim establish that the whole proposed route is legal? Use the full route and closure rule to explain.