3 string tension questions

I am seeking a comparison of strings with respect to:
1- Low tension
2- Normal tension
3- High tension

QUESTION:
A- Which tension will give maximum sustain: 1, 2, or 3?
B- Which tension will give greatest loudness: 1, 2, or 3?
C- Which tension will offer greatest playability: 1, 2, or 3?

Under your question...medium and low tensions will allow your strings to vibrate better...
Loudness comes from the high tension, density of the string and gauge
lower tension will offer the best playability and comfort....

lower tension you lose out on clarity and volume, but get a sweeter tone

In addition to what Stan said, I have found that in almost all cases high tension strings tend to have better, more consistent, intonation up the neck than low tension strings do.

Coming from guitar, I really prefer more tension than most ukulele players, but it's not for everybody.

You can go too far with high tension, too. Some very lightly built ukes, like my KoAloha ukes, just really don't like high tension strings at all - it clamps the sound right down.

At the other end of the scale, some heavier ukes really need fairly high tension strings to develop their best sound.

John