In which of the following products can caffeine be found?

Caffeine (C₈H₁₀N₄O₂) is a central nervous system stimulant from the methylxanthine class that enhances cognitive function, alertness, and attention. It functions by blocking adenosine receptors, which increases the release of acetylcholine, a neurotransmitter. Caffeine stimulates the central nervous system, heart, muscles, and blood pressure control centers. It is naturally present in coffee, tea, cocoa, and numerous other products including guarana and yerba mate. In total, caffeine can be found in over 60 different products consumed worldwide.