Correct Answer: Open

Solution : The third option is the correct answer.

"Discreet" means being careful, circumspect, or showing good judgement in speech and behaviour, especially in order to avoid causing offence or to maintain privacy. On the other hand, "open" in this context serves as an antonym, signifying transparency, a lack of concealment, and a willingness to share information openly.

The meanings of the other options are as follows:

• Release refers to setting something free, allowing something to escape, or making something available.
• Zenith is the highest point or culmination of a process, achievement, or celestial object's path.
• To lose means being deprived of or ceasing to have something.

Therefore, the correct answer is open .