Non-count nouns, also known as uncountable nouns, are nouns that cannot be counted or quantified as discrete units. They represent concepts, substances, or qualities that are considered as a whole and cannot be separated into individual elements. Examples of non-count nouns include water, sugar, information, money, and furniture.

Among the four options given, the expression "much" can be used with non-count nouns. Here's an explanation of why the other options are not suitable for non-count nouns:

a) "a few": This expression is used with countable nouns to indicate a small number or quantity. It cannot be used with non-count nouns because they cannot be counted as individual units.

b) "many": This expression is also used with countable nouns to indicate a large number or quantity. It cannot be used with non-count nouns for the same reason as "a few".

c) "these": This is a demonstrative pronoun used to indicate specific objects or people in proximity to the speaker. It cannot be used to quantify or describe non-count nouns.

d) "much": This expression is used to quantify or describe non-count nouns. It indicates a large amount, quantity, or degree. For example, "There is much water in the lake" or "He doesn't have much money".

In summary, "much" is the only expression among the given options that can be used with non-count nouns. It is important to understand the distinction between countable and non-countable nouns in English grammar to use appropriate expressions and quantifiers.