Select the most appropriate option to fill in the blank.

He is ______ poorer than all his friends.

much

The most appropriate option to fill in the blank is much.

The sentence is about the speaker comparing the wealth of the person to the wealth of their friends. The word "much" is the most appropriate word to use because it means "to a great extent". It is the most appropriate word to use in this context because it describes how much poorer the person is than their friends.

The other options are not as appropriate.

• More means "in addition to" or "to a greater extent". This is a possible option, but it is not as specific as "much". "Much" specifically describes how much poorer the person is than their friends.
• Very means "to a great extent". This is a possible option, but it is not as strong as "much". "Much" specifically describes how much poorer the person is than their friends.
• Most means "the greatest in amount or degree". This is not a possible option because it does not make sense to say that the person is the most poorer than all their friends.
• Not much means "a small amount". This is not a possible option because it does not make sense to say that the person is not much poorer than all their friends.