From the given options choose the one which is opposite in meaning to the word given below 

DENSE 

Sparse

The word that is opposite in meaning to dense is sparse.

• Dense means having a high concentration of something; compact.
• Sparse means having a low concentration of something; scattered.

The other options are not opposites of dense.

• Crowded means having a lot of people or things in a small space.
• Dark means not having much light.
• Transparent means allowing light to pass through so that objects behind can be seen.