Answer:
The correct answer is iron.
Step-by-step explanation:
Iron is required to produce red blood cells, which transport oxygen all through the body. At the time of pregnancy, one requires more iron as the volume of the blood enhances and the development of baby's blood also takes place.
In order to include more iron in the diet, one should comprise at least two servings of chicken, meat, legumes, fish, and nuts each day. One should consume cereals, whole-green bread, and green leafy vegetables regularly. In the case of certain women who are not able to get adequate amount of iron from the food, they need to get an iron supplement.