Warming - The word ‘warming’ refers to ‘make or become warm'. This has a very different meaning to the given word. It is not the required synonym. So, this is an incorrect option.
Touching - The word ‘touching’ refers to ‘arousing feelings of sympathy or gratitude'. This has a completely different meaning to the given word. It is not its synonym. So, this is an incorrect option.
Glittering - The word ‘glittering’ refers to ‘shining with a shimmering or sparkling light'. This word has the exact same meaning as the given word. It is the synonym of ‘scintillating’. So, this is the correct option.