The highest mountain in China is: b) Yellow Mountain c) Mt Himalaya. I have already ruled out a and d.
Actually the answer is neither of the two choices you have left. Some of this depends on whether or not you consider Tibet to be a part of The People's Republic of China. The Yellow Mountains are called Huangchan and are located in eastern China. The tallest peak in this chain is called Lotus Peak and at 1,864 meters isn't even close to the tallest peak in the country. There is no peak called Mount Himalaya. Mount Hymalaya can refer to Mount Everest, the tallest peak in the world (8,848 meters). The summit of Mount Everest is on the exact border between China and Nepal if you consider Tibet to be a part of China. It is part of a larger mountain chain called the Himalayas.
The tallest peak that is entirely within the borders of China/Tibet is Kongur Tagh (7,649 meters) in the extreme western part of China.