a, b, c, & d.
I get my pile of root in the bottom of the strainer...twist the excess strainer fabric into somewhat of a tail...put my root ball in the water and let the 'tail' hang out the side...then i can use both hands to really pinch and knead in the water with full force...turn the root ball different directions to make sure i squeeze it all...then every couple minutes i pull it above the water and do a very thorough 'twist-squeeze'...re-submerge and repeat for about 10min, always ending on the twist-squeeze, and usually flipping the 'tail' into the final twist, because it often soaks up water along the way. the twist really gets the most moisture out.
Some people do one-handed squeezing, just clenching their fist repeatedly. But that looks like it would be less effective and take longer, to me. It still works though...