How does a sarcomere shorten using the sliding filament mechanism of muscle contraction?

A) Actin and myosin filaments shorten and slide past each other.
B) As they slide past each other, actin filaments shorten, while myosin filaments do not shorten.
C) Actin and myosin filaments do not shorten, but they do slide past each other.
D) As they slide past each other, myosin filaments shorten, while actin filaments do not shorten.