The option that represents thy type of reading which is used to determine the availability of minerals is D. all of the above. Depending on the situation, as well as the type of a mineral, scientists will use radioactivity, magnetism, or gravity in order to determine how much of a mineral there is in a certain area. Some of these techniques are good for one type of a mineral, and some for another, but these scientists use all three types of readings in order to determine what they need.
