Select a figure from amongst the four alternatives, which when placed in the…

Concept: In a figure-completion matrix, three of the four cells already share one structural rule — here, each cell is a finely subdivided grid combining vertical (column) lines and horizontal (row) lines, just with the exact split between the two varying slightly cell to cell. Solving the matrix means finding the completion that keeps that same crisscross density instead of dropping lines from one direction over a large stretch of the cell.

Application: Reading the three given cells of the master figure:

• Top-left cell: a fine grid built from BOTH narrow vertical strips and horizontal strips running through it.

• Top-right cell: the same style of fine grid — narrow vertical divisions continue, combined with horizontal divisions across part of the cell.

• Bottom-left cell: again a fine grid, this time with the horizontal divisions dominant, combined with vertical divisions across part of the cell.

So the missing (fourth) cell must also be a fine grid that keeps BOTH vertical and horizontal internal lines active through virtually the whole cell — not one that drops an entire direction of lines over a large area.

Cross-check:

• The option that blanks out one whole corner cell with no internal lines at all breaks the density the other three cells establish.

• The option whose lines stop after the top portion, leaving the entire lower half of the cell undivided, also fails to carry both directions through the whole figure.

• The option that blanks out the opposite corner has the same problem, just mirrored.

• Only the completion that keeps the crisscross of vertical and horizontal lines running through nearly the whole cell — matching the density of the other three cells — continues the pattern correctly.

That fully-crossed grid is the figure that belongs in the blank space.