The correct answer is C. pointers.
A pointer is a variable that stores the address of another variable. It is used to access the value of the variable that it points to. For example, if x is a variable, then &x is a pointer to x. The value of &x is the address of x in memory.
Subscripts are used to access elements of an array. For example, if arr is an array of integers, then arr[0] is the first element of the array, arr[1] is the second element, and so on.
Holders are not a technical term in computer science. It could refer to a variable, but it could also refer to something else.
Indicators are not a technical term in computer science. It could refer to a variable, but it could also refer to something else.