Which of the following effects can caffeine cause?

Caffeine is widely known for its stimulant properties, primarily affecting the central nervous system. One of the most recognized effects of caffeine consumption is increased wakefulness. Caffeine works by blocking adenosine receptors in the brain, which are responsible for promoting sleep and relaxation. As a result, the inhibition of these receptors leads to enhanced alertness and decreased feelings of fatigue, making it easier for individuals to stay awake and focused.

This effect on wakefulness is well-documented in scientific literature, and it is one of the primary reasons many people consume caffeinated beverages, especially in the morning or during periods when they need to maintain high levels of attention and performance.