Which of the following formulations cannot be made into a liquid formulation?

The formulation that cannot be made into a liquid formulation is the extruded block. Extruded blocks are solid formulations that are created through a process where materials are forced through a die to create a specific shape. This method produces a dense and solid structure, which makes it unsuitable for transformation into a liquid form.

Liquid formulations typically involve substances that can be dissolved or suspended in liquids, allowing for easy application and absorption. In contrast, extruded blocks are intended for use in formats that do not require a liquid state, such as for baiting or direct placement in the environment where they will gradually release active ingredients.

Other formulations like suspension concentrates and granular baits can be mixed with liquids or formulated in a way that allows for easy application in a liquid format. Therefore, the extruded block stands out as the only option that does not lend itself to being made into a liquid formulation.