This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to do a mountain pose in yoga
Determine if you are well enough.
This pose requires balancing, and if you are unable to balance properly, you might compromise your safety. If you have headaches, low blood pressure, dizziness or lightheadedness, you shouldn't practice the mountain pose.

Available choices:
[I] Learn the benefits of tadasana. You can experience a number of benefits from the mountain pose, including : Strengthening your legs.
[II] One serious health concern is that you may injure yourself or put unnecessary stress on your spine. An appropriate seated posture for this pose is sitting straight with your pelvis tucked in, and your feet touching the floor.
[III] Anyone who has time to adjust and get comfortable, with or without a medicine ball or foam ball, should do the mountain pose. Fill the space between your shoulders with foam.
[IV] Also, before you test your balance, make sure you are ready physically to do this pose. You should be able to complete the mountain pose up to five times a day for six weeks.
The answer is:
[I]