Which of the following statements are implicit in developing the critical path network?1) Only one time estimate is required for any activity2) Time only is the controlling factor at this stage3) Time and cost both are controlling factors at this stage4) Critical events may have positive, negative, or zero float

• A. 1 and 2 only
• B. 1 and 3 only
• C. 1 and 4 only
• D. 2 and 4 only