HNO3 in pure state is colorless but it is often of yellow color. It is due to (A) Unstable structure — AITS & Test Series Chemistry Question

Question

HNO3 in pure state is colorless but it is often of yellow color. It is due to (A) Unstable structure of HNO3 which immediately changes to 2 NO (B) Photochemical decomposition in presence of sunlight (C) Interaction of atmospheric gases with HNO3 (D) Conversion of HNO3 into 2 NO