Solution Method D

Solution Method D is aimed at the elimination of options. The effective solution is only by solving method A.
This solution method has 3 variants.

Solution Method D1 ( "Hidden Pairs - by Row")

Look row by row or an option that is only two times in a row.
If the cells in which they occur exactly match with another option for two times in a row, these few cells that contain numbers.
This allows the other options in these two cells are removed.

For example:
In the puzzle, the cells C3 and I3 both options 2 and 9.
Therefore, the other options from these two cells are removed.

Solution Method D2 ("Hidden Pairs - by Column")

View column for a column or an option that is only two times in this column.
If the cells in which they occur exactly match with another option for two times in this column, these few cells that contain numbers.
This allows the other options in these two cells are removed.

For example:
In the puzzle, the cells C1 and C7 both options 2 and 9.
Therefore, the other options from these two cells are removed.

Solution Method D3 ("Hidden Pairs - by Block")

Look for block or a block that option is only two times in this block.
If the cells in which they occur exactly match with another option for two times in this block, these few cells that contain numbers.
This allows the other options in these two cells are removed.

For example:
In the puzzle, the B9 cells C8 and C9-A7 block in both the options 1 and 7 contain.
Therefore, the other options from these two cells are removed (in this If the option 6 from cell C8).

Hidden Triples / Quads Hidden

The above solution methods are repeated for 3 options ("Hidden Triples") and 4 options ("Hidden Quads").

For example:
In the puzzle, the cells I7, I8 and I9 only the numbers 2, 3 and 4 contain.
Therefore, the other options are removed from these cells.

Hidden Quads For example:
In the puzzle, the cells A9, B9, D9 and G9 only 9 in row the numbers 1 or 3 or 5 or 9. Therefore, the other options are removed from the cells A9, B9, D9 and G9.