Explanation inline...
The combination of an aging population and adverse behaviors such as obesity and smoking will create epidemics of diabetes, heart failure, and other diseases that last a lifetime, which are difficult to treat.A. The combination of an aging population and adverse behaviors such as obesity and smoking will create epidemics of diabetes, heart failure, and other diseases that last a
lifetime, which are difficult to treat.
=> "which" modifies lifetime. Incorrect. It should modify the diseases.
B. The combination of an aging population and adverse behaviors like obesity and smoking
create epidemics of diabetes, heart failure, and other diseases that lasts a lifetime and are difficult to treat.
=> changes the meaning with "create". The original sentence says that it will create. (B) says that they regularly do create. Also, use of "create" is wrong. Should be creates as it talks about the "combination".C. The combination of an aging population and adverse behaviors such as obesity and smoking
creates epidemics of diabetes, heart failure, and other diseases that lasts a lifetime and are difficult to treat.
=> same as above. Creates instead of will create.
D. The combination of an aging population and adverse behaviors such as obesity and smoking will create epidemics of diabetes, heart failure, and other diseases that last a lifetime and are difficult to treat.
=> difficulty of treating and lasting a lifetime correctly modify the diseases. Will create preserves meaning. Create correctly modifies the combination.E. The combination of an aging population and adverse behaviors like obesity and smoking create epidemics of diabetes, heart failure, and other diseases that lasts a lifetime and are difficult to treat.
=> incomplete sentence stub.