NTDs are caused by a vast range of different parasites such as *
A. amoebae
B. bacteria
C. viruses
D. all of the above

More than a billion people—one-sixth of the world’s population, mostly in developing countries—are infected with one or more of the neglected tropical diseases (NTDs). Several national and international programs (e.g., the World Health Organization’s Global NTD Programs, the Centers for Disease Control and Prevention’s Global NTD Program, the United States Global Health Initiative, the United States Agency for International Development’s NTD Program, and others) are focusing on NTDs, and fighting to control or eliminate them. This review identifies the risk factors of major NTDs, and describes the global burden of the diseases in terms of disability-adjusted life years (DALYs).

Explanation:

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)