The lovers were meeting each other secretly, but their . . . . . . . . affair was soon known to everyone.

clandestine
candid
unknown
covert

The correct answer is: A. clandestine

Clandestine means done or happening in secret, especially so as to avoid official notice or attention.

In the given sentence, the lovers were meeting each other secretly, but their affair was soon known to everyone. This means that their affair was clandestine, but it was eventually discovered.

The other options are not correct because:

  • Candid means frank and open, especially in speech.
  • Unknown means not known or familiar to someone.
  • Covert means secret or hidden.

I hope this helps! Let me know if you have any other questions.