ways of determining wheather the circular array is full or empty include which of the following: a$)$ use a counter or boolean data attribute or sacrifice one array location to indicate the index before the front element, b$)$ use a counter or boolean data attribute or sacrifice one array location to indicate the index of the element after the back element, c$)$ use a boolean flag or maintain a counter or have a floating pointer to indicate the front of the queue, d$)$ use a flag to indicate wheather it is full or empty or use two empty elements reserved to indicate the front and back indexes