Final answer:
Option (c) 'Negative; internal energy will decrease' indicates an exothermic process where ΔH is negative due to the release of energy, aligning with our understanding of enthalpy changes.
Step-by-step explanation:
The question is asking which of the given scenarios will result in a change in enthalpy (ΔH) that is always negative. From the provided information, we can deduce that when energy is released during an exothermic process, the change in enthalpy is negative (ΔH < 0). Therefore, we are looking for an option where internal energy decreases as a result of energy release. Option (c) 'Negative; internal energy will decrease' is the correct one because a negative change in enthalpy implies that the reaction is exothermic and releases heat, causing a decrease in the system's internal energy.