Final answer:
If Gabriela is engaged in a complex task, she is most likely to experience inattentional blindness and not notice the stray dog, as our attentional focus can limit our perception of other stimuli.
Step-by-step explanation:
The question is about how attention affects our perception of the environment, particularly when we are focused on a task. According to the lecture on Attention, the most likely scenario for Gabriela, who loves animals, when encountering a stray dog by the side of the road is a) Gabriela is unlikely to notice the dog if she's engaged in a complex task.
This phenomenon is known as inattentional blindness, where a person fails to notice something completely visible because their attention is engaged elsewhere. This was famously demonstrated in the study by Simons and Chabris, where participants failed to notice a person in a gorilla suit during a basketball passing task. Gabriela's love for animals would not supersede the cognitive limitations imposed by her focus on a complex task.