Study the diagram and identify the region representing teachers who are Indian and Chinese.

​Logic: To determine the number that represents the teachers who are Indian and Chinese, identify the numbers that are common to the region of the diagram that represent all Teachers, Indian, and Chinese. The shaded area represents the required region.​

Therefore, the number is → 3

So, from the above, 3 is the only number that represents the teachers who are Indian and Chinese.

Thus, the correct answer is (d).