The operator used to get value at address stored in a pointer variable isa.*b.&c.&&d.||

To evaluate the options given in the question, let's analyze each operator in the context of pointer dereferencing and referencing in programming, specifically in languages like C or C++.

Breakdown of Operators

1. * (Dereference Operator): This operator is used to get the value at the address stored in a pointer variable. For example, if b is a pointer, *b will give the value at the address contained in b.

2. & (Address-of Operator): This operator is used to get the address of a variable. For instance, if c is a variable, &c provides the memory address of c.

3. && (Logical AND Operator): This operator is used for logical conjunction and does not relate to pointers or addresses directly.

4. || (Logical OR Operator): Similar to &&, this operator is used for logical disjunction and is not applicable for getting values via pointers.

Conclusion

Given these definitions:

• The operator used to get the value at the address stored in a pointer variable is *.

Thus, the correct answer is *.