Correct Answer: Stubborn

Solution : The correct choice is the third option.

This means refusing to change one's mind or course of action. The word adamant means refusing to be persuaded or to change one's mind, often implying a stubborn determination. Hence, "stubborn" is the correct synonym for "adamant".

The meanings of the other options are as follows:

• Flexible : It means being easily adaptable or able to change.
• Soft : It means yielding or being easily influenced, which is the opposite of being stubborn or determined.
• Adaptable : It means being capable of changing or adjusting to different circumstances