Concept:The phrase Subhana Rabbiyal 'Azim wa bi Hamdihi is the prescribed glorification of Allah for the position of Ruku' (bowing) during the prayer.
Explanation:In every Muslim prayer, each posture has its own particular words of remembrance.
While in Ruku', the worshipper humbly bows and praises the might of Allah.
The Prophet (SAW) directed that one should say Subhana Rabbiyal 'Azim (Glory be to my Lord, the Almighty).
The full wording, Subhana Rabbiyal 'Azim wa bi Hamdihi, therefore belongs to the bowing position.
In contrast, during Sujud, the wording changes to Subhana Rabbiyal A'la (Glory be to my Lord, the Most High).
The remaining options, Julus (sitting) and Qiyam (standing), also have their own distinct supplications.
Since the phrase contains Rabbiyal 'Azim (the Almighty), it can only be linked to Ruku'.
Answer:C. Ruku'