By month 2, which of the following is true about development?

• A. Brain waves are detectable
• B. Lung development complete
• C. The heart stops beating
• D. Limb buds disappear

Answer: (A)

The main idea here is the timeline of early fetal development and when the nervous system begins to show activity. By about eight weeks after conception (the end of month two), the brain and spinal cord have formed from the neural tube, and neural activity starts to occur. This activity becomes detectable as brain waves, indicating that the central nervous system is functioning even at this early stage. That’s why the statement about brain waves being detectable is true.

Lung development complete is not accurate by month two—the lungs are still developing and won’t be fully formed until much later. The heart stopping beating would be a fatal event, and by this time the heart has already begun beating and continues to do so. Limb buds appear earlier in development and don’t disappear by month two; they continue to grow into arms and legs.