Three scenarios are given in parts a through c below. For each​ scenario, determine the sampling method used by the managers. ​a) The managers select a single branch at random and survey every employee of that branch. A. The managers used a systematic sample. B. The managers used a multistage sample. C. The managers used a cluster sample. D. The managers used a stratified sample. E. The managers used a simple random sample. ​b) The managers use the company​ e-mail directory to contact every 3030th employee on the list. Choose the correct sampling method below. A. The managers used a cluster sample. B. The managers used a multistage sample. C. The managers used a stratified sample. D. The managers used a systematic sample. E. The managers used a simple random sample. ​c) The managers split the company into​ divisions, with each division containing employees that have similar jobs. Within each​ division, they select a SRS of employees to contact. Choose the correct sampling