Which of the Following Are Continuous Random Variables?​

Multiple Choice

Which of the following are continuous random variables?​
I. The weight of an elephant
II. The time to answer a questionnaire
III. The number of floors in a skyscraper
IV. The square feet of countertop in a kitchen

A) ​I and II only
B) ​III and IV only
C) ​I, II and IV only​
D) ​I, II, II, and IV