Final answer:
The nurse should instruct the client with COPD and cor pulmonale to weigh themselves daily and report a gain of 2 lb in 1 day.
Step-by-step explanation:
The nurse should provide the client with chronic obstructive pulmonary disease (COPD) and cor pulmonale instruction to "Weigh yourself daily and report a gain of 2 lb in 1 day."
This is because weight gain can indicate fluid retention, which can worsen COPD symptoms and exacerbate cor pulmonale. Monitoring weight is important to detect changes in fluid status and adjust treatment accordingly.