The correct option is A True
Hydrogen burns with a pale blue flame that is nearly invisible in daylight. The flame may appear yellow if there are impurities in the air like dust or sodium. When hydrogen is “burning”, it undergoes a chemical reaction where it combines with oxygen to form water releasing a lot of energy as:
2H2+O2→H2O+Energy
a lot of energy is released by hydrogen when it combusts, and most of this energy is released in the form of heat. Heat causes gases to expand, and since a lot of heat is released the gaseous mixture (hydrogen, oxygen remaining from and water vapor liberated from the reaction) and the air adjacent to it expands very quickly, such that the gas molecules break the sound barrier. That is the “pop” sound appears upon burning of hydrogen in air.
Therefore, its true that A gas that burns with blue colour flame giving 'pop' sound is Hydrogen.