Final answer:
The situational influence that affects a consumer's decision-making process is the physical surroundings, as it is a factor external to the consumer's personal characteristics.
Step-by-step explanation:
The situational influence that can impact the consumer purchase decision process from the options provided is d. The physical surroundings of a consumer. This element encompasses factors such as the shopping environment, ambiance, and even the social setting in which the consumer makes purchasing decisions. On the other hand, a consumer's lifestyle, advertisements viewed in the past, and personal values, beliefs, and attitudes are considered personal and psychological influences, rather than situational. Social psychology emphasizes how situational factors can strongly influence attitudes, behaviors, and decision-making processes.