Fill in the blanks with the most appropriate option:-

Not to speak of food, ……. water was not available there.

even

The correct option to fill in the blanks is even.

The idiom "not to speak of" is used to introduce something that is so obvious that it does not need to be mentioned. In this sentence, the speaker is saying that food was so scarce that even water was not available. The word "even" is the most appropriate word to use in this context, as it emphasizes the scarcity of water.

The other options are not as appropriate:

• As is used to introduce a clause that explains or expands on something that has already been said. It is not as appropriate as "even", as it does not convey the same sense of emphasis or contrast.
• And is used to join two or more clauses that are related in meaning. It is not as appropriate as "even", as it does not convey the same sense of scarcity or lack.
• Also is used to add an additional piece of information to something that has already been said. It is not as appropriate as "even", as it does not convey the same sense of contrast or surprise.