What are the requirements for the flexion test of ladder rungs/platforms?

a. A pre-load of 200 N must be applied for 1 minute before the test.
b. A test load of 2,600 N must be applied for 1 minute in the middle of the longest (weakest) rung/platform.
c. The maximum permanent deformation must be 0.5% of the interior width after the load is removed.
d. The ladder must be twisted 10 times clockwise and 10 times counterclockwise with a torque of 50 Nm applied at the midpoint of the rung.
e. The ladder must be extended to a length at least equal to the space between rungs/platforms and placed in a vertical position.
a) a, b, c, d, e
b) a, b, c, d
c) b, c, d, e
d) a, c, d, e