No country can . . . . . . . . to practice a constant, rigid foreign policy n view of the world power dynamics.

The correct answer is C. afford.

To afford something means to have enough money or resources to do or have it. In this case, it means that no country has the resources to maintain a constant, rigid foreign policy in view of the ever-changing world power dynamics.

The other options are incorrect for the following reasons:

• A. obliviate means to make someone forget something. This is not the meaning of the sentence.
• B. anticipate means to expect something to happen. This is not the meaning of the sentence.
• D. envisage means to imagine or picture something in one’s mind. This is not the meaning of the sentence.
• E. visualise means to see something in one’s mind. This is not the meaning of the sentence.