Final answer:
In electrophilic aromatic substitution reactions, the major products are determined by the directing effects of substituents on the aromatic ring and the stability of intermediary carbocations, rather than the reaction temperature.
Step-by-step explanation:
In electrophilic aromatic substitution reactions, the major organic product(s) are determined by the stability of the intermediate carbonation formed during the reaction. The reaction is influenced by the presence of substituents on the aromatic ring which can either activate or deactivate the ring towards electrophilic attack, directing the incoming electrophile to specific positions on the ring. However, the question mentions the temperature of the reaction, which, while important in the kinetics of the reaction, typically is less influential on the product distribution unless the reaction involves different pathways that might compete at different temperatures.
During the mechanism, an aromatic pi bond attacks a strong electrophile, generating a carbocation intermediate. Subsequent deprotonation re-establishes the aromatic system. Directing effects of substituents and the stability of the carbocation intermediate primarily determine the product formed, rather than the reaction temperature. For example, electron-donating groups direct to ortho and para positions, favoring substitution there, while electron-withdrawing groups direct to the meta position.