Essential Electrical (Pty) Limited, a South African manufacturing company, supplies and installs its generators and inverters throughout South Africa. Indicate which of the following is useful for Essential Electrical to improve its operating margin. Select one or more: o a. Buying parts in bulk from suppliers at a discount. o b. Switching suppliers to cheaper suppliers. O c. Changing equipment equipment. manufacturing to cheaper O d. Reducing manufacturing equipment stoppages by increasing maintenance. O e. Training workers to be more efficient. O f. Increasing sales through marketing efforts. Essential Electrical (Pty) Limited, a South African manufacturing company, supplies and installs its generators and inverters throughout South Africa. Indicate which of the following is useful for Essential Electrical to improve product gross margins. Select one or more: O a. Buying parts in bulk from suppliers at a discount. O b. Switching suppliers to cheaper suppliers. O c. Changing equipment equipment manufacturing to cheaper O d. Reducing manufacturing equipment stoppages by increasing maintenance. O e. Training workers to be more efficient. o f. Increasing sales through marketing efforts