Concept:The statement that is recited only in the iqamah, and not in the adhan, is the key difference between the two calls.
Explanation:The adhan is the first call to prayer, inviting Muslims to the mosque.
The iqamah is the second call, made just before the prayer begins.
Both calls contain similar phrases such as "Allahu Akbar" and the two shahadahs.
The unique phrase within the iqamah is "Qad qamatis-salat", which means "The prayer is now ready."
This phrase tells worshippers that the prayer is about to start.
Because this statement is recited in the iqamah and never in the adhan, it is what distinguishes the iqamah from the adhan.
Answer:Option C: Qad qamatis-salat.