Final answer:
The statement is false because adding "D" at index 3 of a zero-based indexed LinkedList would insert it before the 4th element, not at the 4th index.
Step-by-step explanation:
The statement "("D".3) would add "D" at the 4th index in the linked list" is intended to describe an operation on a LinkedList of String objects in a programming context. Specifically, it seems to relate to Java programming, as the LinkedList class and its associated methods, such as add(int index, E element), are part of Java's collections framework.
In Java, indexing is zero-based, meaning that the first element has an index of 0. Therefore, adding an element at the 4th index would actually insert it between the 4th and 5th existing elements. Given the example list [A, B, C, D, E, F], the index positions are 0 for A, 1 for B, 2 for C, 3 for D, 4 for E, and 5 for F. Hence, if "D" is inserted at index 3 (the fourth position due to zero-based indexing), it would be placed before the current D, resulting in [A, B, C, "D", D, E, F]. So, the statement given is False.