Final answer:
Iron-fortified rice cereal is generally recommended as the first solid food to introduce to infants due to its ease of digestion and low allergenic potential.
Step-by-step explanation:
When introducing infants to solid food, it is recommended to begin with an iron-fortified cereal. The best option to start with is A. Iron-fortified rice cereal as it is less likely to cause allergic reactions compared to other cereals and it is easy to digest for infants. Iron is a crucial nutrient in an infant's diet, and rice cereal is commonly fortified with it to help prevent iron deficiency. Since rice cereal is very bland, it also has a minimal influence on the taste preferences of the baby. It's important to introduce one single grain cereal at a time to monitor for any potential food allergies or intolerances.