The following data have been collected for four different cost items.

$\backslash$table$[[,$Cost at $100$ units,Cost at$],[$Cost Item,,units$],[$w$,$$$,8,000,$$$,10,560],[$X$,$$$,5,000,$$$,5,000],[$Y$,$$$,6,500,$$$,9,100],[$Z$,$$$,6,700,$$$,8,580]]$

The following data have been collected for four different cost items.

$\backslash$table$[[$Cost Item,Cost at$,$Cost at$],[100$ units,,units$],[$w$,$$$,8,000,$$$,10,560],[$X$,$$$,5,000,$$$,5,000],[$Y$,$$$,6,500,$$$,9,100],[$Z$,$$$,6,700,$$$,8,580]]$

Which of the following classifications of these cost items by cost behavior is correct?

a$.$ Variable

Costx

Cost $Y$

Cost Z

b$.$ Mixed

Fixed

Mixed

Variable

c$.$ Variable

Fixed

Variable

Mixed

d$.$ Mixed

Fixed

Variable

Variable

Mixed

Mixed

Answer $$