The body of anyone infected by virus X will, after a week, produce antibodies to fight the virus. The antibodies will increase in number for the next year or so. There is now a test that reliably indicates how many antibodies are present in a person's body. If positive, this test can be used during the first year of infection to estimate within a month of accuracy when that person became infected by the virus.

Which one of the following conclusions is best supported by the statements?

a) Antibodies increase in number only until they have defeated the virus.

b) Without the test for antibodies, there is no way of establishing whether a person has virus X.

c) Antibodies are produced only for viral infections that cannot be fought by any other body defenses.

d) If a person remains infected by virus X indefinitely, there is no limit to the number of antibodies that can be present in the person's body.

e) Some people infected by virus X may fail, for a period of time, to exhibit infection if tested by the antibody test.

4. Selective Serotonin Reuptake Inhibitors (SSRIs) are a class of antidepressants that ease depression by increasing the brain's ability to reabsorb serotonin molecules, which are associated with moods of happiness in some people. Serotonin levels and their absorption can be significantly increased with a schedule of regulated sleep and exercise.

Which of the following can be correctly inferred from the statements?

a) Individuals who regularly get plenty of sleep and exercise are not at risk for depression.

b) Individuals who do not take SSRIs run a high risk of developing dangerously low levels of serotonin over time.

c) When combined with a program of regulated sleep and exercise, SSRIs are the most effective method of easing depression in humans.

d) A program of regulated sleep and exercise can potentially ease depression in some individuals.

e) Only regulated sleep is necessary to maintain healthy

Plz answer both are correct and ecplain