Q. A 26-year-old man comes to the fertility clinic with his wife due to failure to conceive. The patient has no significant medical history apart from a recurrent chest infection. He infrequently smokes marijuana. Vital signs show no abnormalities. Cardiac examination reveals a cardiac apex in the right fifth intercostal space midclavicular line. No murmurs or additional heart sounds are heard. Recent semen analysis demonstrated immotile sperm. Which of the following embryological processes was likely disrupted in this patient?