According to Hedley Bull, great powers “manage their relations with one another in the interest of international order” through:

(i) preserving the general balance of power,

(ii) seeking to avoid or control crises in their relations with one another, and

(iii) seeking to limit or contain wars among one another. They exploit their preponderance in relation to the rest of international society by

(iv) unilaterally exploiting their local preponderance,

(v) agreeing to respect one another’s spheres of influence, and

(vi) joint action, as is implied by the idea of a great power concert or condominium”. 

Therefore, the correct option is A.