Final answer:
The most common cause of death in chronic lymphocytic leukemia (CLL) is infection.
Step-by-step explanation:
The most common cause of death in chronic lymphocytic leukemia (CLL) is infection. CLL is associated with a weakened immune system, which increases the risk of developing opportunistic infections. The hypogammaglobulinemia that occurs in CLL predisposes individuals to infections and further contributes to immunodeficiency. Therefore, infection is the primary cause of death in CLL.