A 66-Year-Old Man Who Lives Alone Has a Severe Myocardial $\mathrm{Ca}^{2+}$

A 66-year-old man who lives alone has a severe myocardial infarction and dies during the night. The medical examiner's office is called the following morning and describes the man's body as being in rigor mortis. This state of rigor mortis is due to which one of the following?

A) Inhibition of $\mathrm{Ca}^{2+}$ leakage from the extracellular fluid and sarcoplasmic reticulum
B) Enhanced retrieval of $\mathrm{Ca}^{2+}$ by the sarcoplasmic reticulum
C) Failure to disengage tropomyosin and troponin from the myosin active sites
D) Absence of ATP preventing detachment of the myosin heads from actin
E) Increased lactic acid production