Answer
The reaction undergoes acid-catalyzed opening of epoxides. The proposed mechanism is shown in the picture.
Work Step by Step
The proposed mechanism is:
Step 1: Protonation of the epoxide activates it toward nucleophilic attack.
Step 2: Back-side attack by the solvent (water) opens the ring.
Step 3: Deprotonation gives the diol product.
Then the product is rotated and a fisher projection is made.