For this question, choose the option opposite in meaning to the word or phrase in italics. The manager became flexible on critical matters.

Flexible means willing to change, adapt, or compromise; capable of bending without breaking. A flexible person adjusts their position or approach easily.

The word opposite in meaning is rigid, which means stiff, unyielding, and not able to be changed or adapted. A rigid manager would be one who refuses to adjust or compromise on any matter - the direct opposite of being flexible.

The other options are not the best antonyms:

• evasive means tending to avoid commitment or providing clear answers. This describes dishonesty or avoidance, not inflexibility.
• serious means showing earnest thought or concern. A person can be both serious and flexible, so this is not an opposite.
• unbendable is close in meaning to rigid and could seem like a valid antonym, but rigid is the standard, well-established antonym of flexible in English usage. Both rigid and unbendable suggest inflexibility, but rigid is the more conventional and widely recognised opposite.