What key factor can influence the effectiveness of study sessions?

The effectiveness of study sessions is significantly influenced by the environment where studying occurs. An optimal study environment can enhance concentration, reduce distractions, and create a more conducive atmosphere for learning. Factors such as lighting, noise level, comfort, and even the presence of other people can impact how well a student can engage with the material. A quiet, organized, and well-lit space typically promotes better focus and retention compared to a chaotic or uncomfortable environment.

In contrast, the other options do not universally support effective study practices. Studying alone may be beneficial for some, but it is not a one-size-fits-all solution. The mere number of hours spent studying doesn’t guarantee comprehension or retention of information; what matters more is how effectively that time is utilized. Additionally, while some individuals may perform well studying late at night, this schedule isn't optimal for everyone and could lead to fatigue and decreased learning efficiency.