please ASAP

choose one answer

Given the following code segment for Stack. What is the value at the top of the stack? 1. Stack color = new Stack(5); 2. color.push("blue"); 3. color.push("red"); 4. color.push(color.top(); 5. color.push("green"); 6. color.push(color.pop(); a) blue b )stack underflow c )green d )red Which of the following represent the worst case input for an insertion sort? Array in sorted order . Array sorted in reverse order . Unsorted array . Large array. In a queue, the initial values of front pointer fr are pointer r should be..........and.........respectively. 0 and -1 0 and 1 -1 and 0 1 and 0 The result evaluating the postfix expression: 2 3 1* +9- 2 -2 -4 4