Final answer:
The older child has an increased risk of kwashiorkor, a severe protein deficiency condition, if weaned early from breast milk without adequate protein in their diet.
So, the correct answer is d) Kwashiorkor.
Step-by-step explanation:
If a mother has a second child within a close time span of the first child, and the first child no longer has access to the mother's breast milk and if other forms of nutrition especially protein are lacking in the child's diet, the older child has a heightened risk of developing kwashiorkor. Kwashiorkor is a protein deficiency illness that is characterized by edema, skin problems, weak muscles, and other serious health issues. This condition is more common in developing countries and can be life-threatening if not properly addressed with a nutritionally adequate diet.
So, the correct answer is d) Kwashiorkor.