Preparing ...c7-c5 in order to restrict White's minor pieces.

This helps Black gain space and bring his king closer, although White had no prospects.

restricting the white knight with a huge advantage.

Preventing an enemy attack with ...b5-b4 and ...a5-a4.

The most consistent choice.

By attacking f2 Black interferes with the plan of Rdg1 and g4-g5.

A less active defence permits 5 f3 with central activity.

Preparing Bc3 with a promising attack.

An excellent measure of restriction, which takes the e4-square away from several black pieces, and soon d5 as well.