A group of people participate in some curriculum, 30 of them practice Yoga, 25 study cooking, 15 study weaving, 6 of them study cooking only, 8 of them study both the cooking and yoga, 7 of them participate all curriculums. How many people study both cooking and weaving?  Choose the correct choice from the following choices
A) 1  B) 2  C) 3  D) 4  E) 5

Rationale: "both cooking and weaving = 25 - ( 6 + 8 + 7 ) = 4 so , the correct answer is d ."
Answer: D