**Concept: The question tests on the basics of Overlapping sets**

**Solution:**

By the principle of Set Theory, the Total = A + B - A ∩ B + (A U B)'

Here A = Those who likes mustard = 84% of 100 = 84

Here B = Those who likes mayo = 68% of 100 = 68

(A U B)' = Those who don't like either mustard or mayo = 0

Therefore A ∩ B = 84 + 68 - 100 = 152 - 100 = 52

**Option B**