3, 5, 7, 1, 2
Since you have to use five of them, numbers 4 and 6 would not go into the plan. The order above is the one that makes most sense to me.
Having weak eye sight is not a lifestyle factor. Your life style is your choice. You choose to smoke, you choose to have friends, and you choose to walk to school. Having weak eye sight is involuntary.
Really, none of these answers are good. leukocytes are the body's general immune cell, and lymphocytes are a type of leukocyte. Antibodies are only used when fighting an infection that your body already has experience with, so I'm guessing it you have to pick from these answers, its "lymphocytes", but it's not really the best answer.
The answer to your question is conduction.
