Concept:Taharah means purification; not every action related to wudu is a complete act of purification.
Explanation:Ghusl is washing the whole body, so it is an act of Taharah.
Istinja is cleaning the private parts after relieving oneself, so it is an act of Taharah.
Tayammum is dry ablution using clean earth when water is unavailable, so it is an act of Taharah.
Istinshaq, however, is only sniffing water into the nose during wudu.
It is a part of wudu, not an independent act of purification by itself.
Therefore, Istinshaq is the option that is not an act of Taharah.
Answer:B. Istinshaq