Final answer:
The correct energy transformation when eating and then bicycling is: chemical energy from food is converted into kinetic energy for movement, which generates heat as a byproduct. So the correct answer is Option D.
Step-by-step explanation:
The description that best explains energy transformations when someone eats dinner and then bicycles is D. chemical → kinetic → heat. When a person eats, they convert the chemical energy found in food into kinetic energy through the process of metabolism as they pedal their bicycle. The kinetic energy is the energy of movement, which when utilized also generates heat as a byproduct due to muscle exertion and energy conversion inefficiencies.