Final answer:
The self-awareness of older drivers varies considerably, depending on factors like individual differences and health conditions. While some older drivers may adjust their driving habits according to their abilities, others may not notice the decline. This self-awareness is crucial for maintaining safety on the road.
Step-by-step explanation:
The question of how self-aware older drivers are does not lend itself to a straightforward answer, but the best option among those provided is "d) It varies." Self-awareness in older drivers can depend on a multitude of factors including individual differences, health conditions, cognitive function, and driving experience. Some older drivers may be quite self-aware and recognize the need to adjust their driving habits, while others might not perceive a decline in their driving abilities.
Regarding the provided information, none of the options explicitly apply to the self-awareness of older drivers. However, it's important to note that with age, senses do not increase as stated in sentence 'b'. In fact, most senses tend to decline with age, which could affect driving abilities. Therefore, older adults must remain self-aware of these changes to ensure safety while driving.
Lastly, the concept of not aging very much yourself through various means of traveling at different speeds pertains to theoretical physics, specifically related to the concept of time dilation as predicted by Einstein's theory of relativity. In that context, sentence 'a' by traveling at a speed equal to the speed of light would theoretically result in less aging, but this is not practically achievable and is unrelated to the self-awareness of older drivers.