Explanation
$$\textbf{Correct option: B}$$
$$\textbf{Solution:}$$
Option A:
$$\bullet$$ Endplate is the sarcolemma area of muscle fiber that interacts with neurons.
$$\bullet$$ Action potential is generated on the end-plate for transfer of neuron signal to the muscle fiber.
Option B:
$$\bullet$$ Excitation-contraction coupling is the sequence of steps occurs during sliding of myofibrils of muscle cells stimulated by an electric impulse generated in the sarcolemma.
$$\bullet$$ It is basically the link between electrical action potential generated and mechanical contraction of muscles.
$$\bullet$$ Calcium ions are released from the sarcoplasmic reticulum during contraction. These calcium ions bind with the troponin to initiate contraction.
$$\bullet$$ So, calcium ions are not released from troponin during excitation-contraction coupling.
Option C:
$$\bullet$$ Calcium ions released from the sarcoplasmic reticulum get bound with troponin during excitation-contraction coupling.
$$\bullet$$ Conformational changes occur in the troponin that causes tropomyosin to move away from myosin-binding sites on actin.
$$\bullet$$ This results in the formation of cross-linkage between actin and myosin fibrils.
Option D:
$$\bullet$$ Energy is produced in the generation of excitation-contraction coupling by hydrolysis of ATP to ADP.
Hence the correct option is option B.
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