Final answer:
At high temperatures, HCl reacts with 1,3-butadiene to produce the 1,4-Addition product in higher yield due to the stability of the extended π system, favoring a thermodynamically controlled pathway. The option (A) is correct.
Step-by-step explanation:
When HCl is reacted with 1,3-butadiene at high temperature, the product that will be higher in yield is the 1,4-Addition product. At high temperatures, 1,3-butadiene tends to undergo a conjugate addition (also known as 1,4-addition), where the HCl adds across the double bond system resulting in the formation of the 1,4-adduct. This results from the stability provided by the extended π system of the diene which allows for the reaction to proceed via a thermodynamically controlled pathway.
The 1,2-Addition product might also be formed, but in significantly lower amounts due to the high temperatures favoring the more stable product. Polymerization and elimination are less likely under the reaction conditions specified for this simple addition reaction. Therefore, option (A) is correct.