‘Family planning’ is a broad term that includes any measures taken to responsibly prevent pregnancy (birth control, contraception, planning, abortions, permanent infertility procedures, etc.).
Birth control, however, is specifically designed to intervene in a woman’s natural hormones to drastically reduce the possibility of pregnancy (much like contraception)
The correct answer is the final option - sickle cell disease and malaria are both potentially lethal diseases.
The other options are incorrect because sickle cell disease is an inherited disease, but malaria is not - it is an infectious disease. However, both of these disease are quite dangerous, and may have severe consequences (such as death) if they are not properly treated.