Match each differential analysis term to its definition.

$\backslash$table$[[$Definition$,$Differential Analysis Term$],[$a$.$ Expected future costs that differ among alternative courses of action.,$],[$b$.$ Decision outcomes that are difficult to measure.,Make$-$or$-$buy analysis$],[\backslash$table$[[$c$.$ Past costs spent that cannot be recovered regardless of the future course of$],[$action chosen.$]],$Qualitative factors$],[\backslash$table$[[$d$.$ Prescriptive analytics technique to determine whether to manufacture a$],[$product in house or to purchase it externally.$]],$Quantitative factors$],[$e$.$ Expected future revenues that differ among alternative courses of action.,Relevant costs$],[$f$.$ Measurable decision outcomes.,Relevant revenues$]]$