Final answer:
The client shows an understanding of heart failure management by limiting sodium intake and knowing when to contact their doctor if they experience significant weight gain or signs of fluid overload.
Step-by-step explanation:
The client with heart failure has indicated an understanding of the teaching through several statements. The most relevant statements that reflect the client's comprehension include statement C) "I am limiting my sodium intake to 2 g daily," and statement E) "I know to call my doctor if I gain 3 lbs or more in 2 days." Contrarily, statement B) "I am trying to decrease my intake of foods with potassium," does not show an accurate understanding of their condition, as patients on diuretics like furosemide often need to maintain adequate potassium intake due to the risk of hypokalemia caused by increased urination.
Loop diuretics such as furosemide work by inhibiting sodium (Na+) and chloride (Cl−) reabsorption in the ascending limb of the loop of Henle, which leads to increased urine production as more sodium and water are excreted.