What is the formula and IUPAC name of the triol also known as glycerin?

Formula:

Chemical structure of propane-1,2,3-triol, also known as glycerin.

Name: propane-1,2,3-triol

Formula:

Chemical structure of propane-1,1,3-triol.

Name: propane-1,2,3-triol

Formula:

Chemical structure of propane-1,2,3-triol, also known as glycerin.

Name: propane-1,2,3-triol

Formula:

Chemical structure of propane-1,2,3-triol, also known as glycerin.

Name:propane-1,1,3-triol