Final answer:
Porcine species (pigs) are most sensitive to hyperthermia during physical restraint due to their inefficient sweating mechanism, making them more prone to heat stress.
Step-by-step explanation:
The species most sensitive to hyperthermia during physical restraint is A. Porcine (pigs). Pigs lack the ability to sweat effectively, which makes them more prone to heat stress and hyperthermia, especially during periods of physical restraint when they cannot take actions to cool themselves down. In contrast, species such as equines (horses) have more efficient cooling systems through sweating, and ovines (sheep) and caprines (goats) are also less susceptible compared to porcines.