Final answer:
The absorption of manganese in the small intestine is very low, typically less than 5 percent. Option b. <25% would be the most suitable answer.
Step-by-step explanation:
The absorption of manganese in the small intestine is very low, regardless of the amount ingested. Only a small percentage of manganese is absorbed by the body. According to the given information, it states that the absorption of copper, a similar mineral, is about 2 to 5 percent in normal subjects. Therefore, it can be concluded that the percentage of manganese absorbed in the small intestine is likely to be less than 5 percent.