Question

adding the prefix de - to the word value makes a word that means
\lessen the worth of.\
\increase the worth of.\
\beyond the worth of.\
\against the worth of.\

Explanation:

The prefix "de -" often implies a reversal or reduction. When added to "value", it forms "devalue". "Devalue" means to make something have less value, which is equivalent to "lessen the worth of".

Answer:

"lessen the worth of."