A:
500 warm up
10x25 @ :30 with sighting (lift your head and 'sight' 4-5 times per lap)
10x25 @ :30 turn at the 'T' (start in the middle of the pool, swim towards the wall, flip at the 'T', don't touch the wall, and swim back to the middle)
main set:
6x75 kick @ 1:30
6x100 swim @ 1:25 or 1:30
4x75 kick @ 1:25
3x200 swim @ 2:40 or 2:50
2x75 kick @ 1:20
2x300 swim @ 4:00 or 4:15
50 easy recovery
10x25 @ :30 (odds: head up all the way, evens: easy swim)
10x25 @ :40 (1st lap: 4 breaths, 2nd lap: 3 breaths, 3rd lap: 2 breaths, 4th: 1 breath, 5th: no breaths, repeat)
200 cool down
*4400 Total*

B:
400 warm up
10x25 @ :40 with sighting (lift your head and 'sight' 4-5 times per lap)
10x25 @ :40 turn at the 'T' (start in the middle of the pool, swim towards the wall, flip at the 'T', don't touch the wall, and swim back to the middle)
main set:
6x50 kick @ 1:30
6x75 swim @ 1:30
4x50 kick @ 1:20
3x150 swim @ 3:00
2x50 kick @ 1:10
2x225 swim @ 4:00
50 easy recovery
8x25 @ :45 (1st lap: 4 breaths, 2nd lap: 3 breaths, 3rd lap: 2 breaths, 4th: 1 breath, repeat)
200 cool down
*3400 Total*

C:
300 warm up
8x25 w/:15 sec rest (sighting: lift your head and 'sight' 4-5 times per lap)
8x25 w/:15 sec rest (turn at the 'T': start in the middle of the pool, swim towards the wall, flip at the 'T', don't touch the wall, and swim back to the middle)
main set:
6x50 kick @ 2:00 (you can use fins for the last 3 50s)
6x75 swim @ 2:00
4x50 kick @ 2:00 (you can use fins for the last 2 50s)
3x150 swim @ 4:00
8x25 @ :60 (1st lap: 5 breaths, 2nd lap: 4 breaths, 3rd lap: 32 breaths, 4th: 2 breaths, repeat)
100 cool down
*2400 Total*