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If ""^(n)C(r-1):""^(n)C(r):""^(n)C(r+1)=...

If `""^(n)C_(r-1):""^(n)C_(r):""^(n)C_(r+1)=2:4:5` then (n,r) is

A

(10,4)

B

(9,7)

C

(8,3)

D

(7,2)

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The correct Answer is:
C
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