Answer:
d) folic acid
Step-by-step explanation:
Neural tube defects (NTD) are birth defects that occur in some specialized regions such as the brain and spinal cord. They are considered and bethink as a complex disorder because they are caused by combination of environmental and multiple genetic factors. Environmental factors include low folic acid intake, maternal use of certain anticonvulsant medications. etc. On the other hand multiple genetic factors can include spina bifida (an phenomena whereby there is incomplete closing of the spine and membranes surrouning the spinal cord at the initial stage of development of fetus in pregnancy.
During pregnancy, folate requirements increase due to the result of rapidly dividing cells related to fetal growth. It is of great advantage that pregnant woman should increase their folic acid supplements intake to (400-800μg daily) prior to conception, this can help and assist to reduce the risk for neural tube defects in the fetus.