This is a question with answer options. Goal: How to build the base for your storage rack?

Which of the following methods is more reasonable for accomplishing this goal?

Choose from:
(a). Use a 2X6 for the center beam and 2X4's for the side beams with the 3" nails to secure the beams at each joint then 1.5" nails to attach the floor boards with a gap for the 5 degree angled 2X6 in the back. Use a leveler to ensure all beams are straight.
(b). Use a 2X6 for the center beam and 2X4's for the side beams with the 3" screws to secure the beams at each joint then 1.5" screws to attach the floor boards with a gap for the 5 degree angled 2X6 in the back. Use a leveler to ensure all beams are straight....I think the answer is
(b).