42 As the ability to travel over great distances becomes easier, the spread of communicable diseases becomes easier. (A)Transferable diseases will stop spreading if human beings’ ability to traverse oceans and mountains increases. (B)The extent to which people move across places is not necessarily related to the increase of infectious diseases. (C)The higher the ability of people to go from one place to another, the less likely is the spread of transmissible diseases. (D)Human mobility seems to increase the possibility of spreading diseases.