The 1-2 point is the key in the solution.
If here, then Black can play and and capture White due to shortage of liberties.
attempts to set up a ko fight. However, connects to the stone and there is no ko.
and lives too, but loses one extra stone.
and is greedy. After makes the large monkey jump, Black dies of a straight three dead shape.
here cannot live. simply plays a honte, and Black is a L-group dead shape.
Because Black lack outside liberties, is possible. If blocks, then onwards cause Black to be trapped in a double damezumari.
If first, then the clamp at is tesuji which kills.