I would agree with your answer of C. As there would need to be calcium to start with and they seem to come from the sarcoplasmic reticulum
Sodium and bromine would form an ionic bond. The one valence electron from sodium would be transferred to the bromine atom in order to obtain octet for both.
Properties of Salt
Crystals or white crystalline powder.
Transparent and colourless in crystalline form – rather like ice.
Crystallises in the isometric system, usually in the form of cubes.
Soluble in water (35.6g/100g at 0°C and 39.2g/100g at 100°).
Slightly soluble in alcohol, but insoluble in concentrated hydrochloric acid.
The constant variable is kinetic energy because of it being in motion constantly.