Consider the following statements: AIDS is transmitted 1. by sexual intercourse. 2. by blood transfusion. 3. by mosquitoes and other blood sucking insects. 4. across the placenta. Of these statements

1. AIDS (Acquired Immunodeficiency Syndrome) is caused by the Human Immunodeficiency Virus (HIV). 2. HIV is primarily transmitted through specific routes: sexual intercourse (vaginal, anal, or oral sex) with an infected person (Statement 1 is correct). 3. It is also transmitted through exposure to infected blood, such as sharing needles or receiving contaminated blood transfusions (Statement 2 is correct). 4. HIV can be transmitted from an infected mother to her child during pregnancy, childbirth, or breastfeeding (across the placenta or during birth/breastfeeding) (Statement 4 is correct). 5. HIV is *not* transmitted by mosquitoes or other blood-sucking insects (Statement 3 is incorrect). 6. Therefore, statements I, II, and IV are correct modes of AIDS transmission.