Ravi took three substances P, Q and R and burnt them one by one. He noted down his observations given below.

i) Substance ‘P’ burns quickly producing heat and light i.e. rapid combustion

ii) Subsance ‘Q’ burns in room temparature on its own i.e spontaneous combustion

iii) Substance ‘R’ burns with the evolution of heat, light and sound explosion. Which of the following statements regarding the given information is correct?