Which of the following is a continuous random variable?

A) The number of employees of an automobile company.
B) The amount of milk produced by a cow in one 24-hour period.
C) The number of gallons of milk sold at Albertson's grocery store last week.
D) None of these choices.

Refer to Mighty Machinery Company. Fenway and Gilbert both worked for Mighty Machinery Company two years ago. Each was single and participated in the company health plan individually. Last year they married each other and participated as employee and one dependent. Two years ago each had doctor bills of $500. This year their combined doctor bills were $1,000. How much less did Fenway and Gilbert pay for medical care and coverage last year as a couple than the year before as two individuals?​