Final answer:
Indexes cannot be used to access structure members of different sizes.
Step-by-step explanation:
In a structure, the members can have different sizes. This means that indexes cannot be used to access them.
For example, in a body-centered cubic lattice, the A and B atoms can be of the same kind or they can be different. If they are the same, the structure is stable. However, if they are different and the B atom is too large to fit into the interstitial space, or if it is so small that the A layers come into contact without sufficient A-B coulombic attractions, the structural arrangement may not be stable.
The statement that indexes cannot be used to access structure members because they can be of different sizes is false. In many programming languages, such as C and C++, structures are collections of variables under a single name. These variables, called members, can indeed be of different types and sizes.
However, each member of a structure has a specific name and the structure has an associated 'dot' or 'arrow' syntax that is used to access these members. Unlike arrays, where indexes are used to access elements, structure members are accessed by their names.
Therefore, the statement is B)False.