The correct answer is "neurons".
Neurons are nerve cells which connect to each other using synapses and form neural networks. They exhibit high levels of specialization and are the primary components of the central nervous system.
Myofibrils are contractile fibers which form the striated muscle cells. Sarcomeres are the structural unit of the myofibrils.
D. The heat is there via convection from the sun
Mutation would be the best answer.
In an endothermic reaction, energy is absorbed which causes the object to heat up.
This is the order from top to bottom rounded; 0.24, 0.28, 0.30, 0.33