In this question, there is a certain relationship between two given numbers on one side of (∶ ∶) and one number is given on another side of (∶ ∶) while another number is to be found from the given alternatives, having the same relation with this number as the numbers of the given pair bear. Choose the correct alternative.63 ∶ 7 ∶∶ 72 ∶ ?

• A. 6
• B. 7
• C. 8
• D. 5