What's one of the main motivations for individuals in the economic system of capitalism?

Well most plainly that would be the accumulation of wealth, monetary gain or in other words self-interest. Roots of this philosophy can be traced to Adam Smith and his monumental work The Wealth of Nations which argues that an individual acting in his own best interest and guided by the principle of justice  benefits himself and  the society as a whole. This can also be looked at from the viewpoint of the rational choice theory on which the profit motive functions.

the correct answer option is: weapons.

explanation:

tensions rose as the two opposing superpowers competed for 'weapons'.

referring to the cold war (1945-1991), the two superpowers, usa and ussr, experienced a phase of struggle and conflict with each other. these two superpowers considered each other as a threat to their survival and thus opted for policies to strengthen their positions.

the two superpowers never went to war with each other directly but competed for weapons to preserve their positions.