"which theory is a model of economic development that explains global inequality in terms of the historical exploitation of poor societies by rich societies? "

Modernization theory

Modernization theory is utilized to demonstrate the method of transformation inside communities. Modernization introduces to a pattern of a reformist transformation from a 'pre-modern'  to 'modern' society. This theory introduced from the beliefs of  Max Weber a sociologist of Germany, which presented the foundation for the modernization paradigm. The theory examines the physiological determinants of a nation while understanding that with support, "traditional" nations can be brought to advancement in a similar manner more developed nations have been.

it is due to the halo effect as the impression of the boy created earlier.on the mind of the principle affected his decision

the answer your looking for is c. : )