The table given below shows the marked price and selling price of 6 articles.

Discount = Marked price - Selling price
J1 = The value of average of discount of article A1, A2, A3 and A4.
J2 = The difference between marked price and selling price of all articles.
What is the value of (J2 - J1)?

A

592.5

B

576.5

C

587.5

D

552.5