A triple riveted butt joint with double straps of unequal width is to be designed for a boiler shell. The pitch of the rivets in the outer row is double the pitch in the inner row and zig-zag riveting is proposed. Which of the following statement is correct?

• A. There are four rivets per pitch length, all in double shear
• B. There are four rivets per pitch length, out of which two are in single shear and two are in double shear
• C. There are five rivets per pitch length, all in double shear
• D. There are five rivets per pitch length, out of which four are in double shear and one is in single shear