The standard deviation of a portfolio: A. is a weighted average of the standard deviations of the individual securities held in that portfolio. B. can be less than the weighted average of the standard deviations of the individual securities held in that portfolio. C. measures the amount of diversifiable risk inherent in the portfolio. D. is a measure of that portfolio's systematic risk.

World systems manufactures an optical switch that it uses in its final product. world systems incurred the following manufacturing costs when it produced 74 comma 000 units last​ year: ​(click the icon to view the manufacturing​ costs.) another company has offered to sell world systems the switch for $ 13.50 per unit. the world systems prepared an outsourcing decision analysis to show the cost per unit of making the switches versus the cost per unit of buying​ (outsourcing) the switches. ​(click the icon to view the outsourcing decision​ analysis.) world systems needs 86 comma 000 optical switches next year​ (assume same relevant​ range). by outsourcing​ them, world systems can use its idle facilities to manufacture another product that will contribute $ 140 comma 000 to operating​ income, but none of the fixed costs will be avoidable. should world systems make or buy the​ switches? show your analysis.