In the following question, four number pairs are given. The number on left side of (-) is related to the number on the right side of (-) with some Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.
Options:

Options

A. 5-15
B. 7-21
C. 9-29
D. 11-33

Answer

B