Diversity indices measure how varied a population or area is. The entropy measure used for diversity is built on Claude Shannon’s information theory, in which the information carried by a system is measured by its entropy.

The index is computed as \(H = -\sum p_i \ln p_i\), where \(p_i\) is the proportion of the i-th group. Because it is Shannon’s entropy measure it is called the Entropy Index and, from its information-theory origin, also the Information Index. It is maximum when all groups have equal shares.

The Delta Index measures how much a group is concentrated in a small area, not information. The Gini Index measures unevenness of a distribution, and the Interaction Index measures the chance of contact between members of two groups; neither is called the Information Index.

Entropy Index option is correct.