Correct option is A
Myelomeningocele is often associated with Arnold–Chiari malformation leading to obstructive hydrocephalus. Tense/bulging anterior fontanelle indicates raised ICP.
Explanation of options: (a) ✔ Correct; monitoring fontanelle detects hydrocephalus, the most common complication. (b) ✘ Intracranial hemorrhage presents with irritability and seizures, not fontanelle bulge monitoring. (c) ✘ Cerebral palsy is a long-term sequela, not detected by fontanelle exam. (d) ✘ Neural tube cannot re-close after birth; not relevant.