The EMG is a recording of: The action potential of the motor nerves supplying the muscle fibers. The contraction forces of the innervated muscle fibers. The action potentials of the innervated muscle fibers.

The correct answer is option B.  The contraction forces of the innervated muscle fibers.

Explanation:

Electromyography or EMG is the study of muscle activity with the help of analyzing electric signals that are burst or generated by the contraction of the muscle fibers. In other words, it is the electrical activity of the skeletal muscles in response to a nerve's stimulation of the muscle.

EMG uses the myoelectric signals to analyze muscle that is generated during the contraction forces of the inverted muscle fibers of the skeletal muscle.

Thus, the correct answer is option B.  The contraction forces of the innervated muscle fibers.

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.