Final answer:
The doctor thinks that Martha's adrenal gland is malfunctioning, causing her issues with dehydration and breastfeeding.
Step-by-step explanation:
The doctor believes that the adrenal gland is malfunctioning in Martha's case. The adrenal gland is responsible for producing hormones that regulate the body's response to stress, including the hormone aldosterone which helps regulate fluid balance and can affect dehydration. If the adrenal gland is not functioning properly, it can lead to issues with dehydration and difficulty breastfeeding.