What will come in place of blank space (_) in the following series
r _ s e _ o s _ r o _ e r _ s e​​

Given: r _ s e _ o s _ r o _ e r _ s e​​

Now, we check each options.

Option (a): r o r e s (Not Follow)

r r s e / o o s r / r o e e / r s s e

Option (b): o r e s o (Follow)​

r o s e / r o s e / r o s e / r o s e

Option (c): o e s r s (Not Follow)​

r o s e / e o s s / r o r e / r s s e

Option (d): r o e s o (Not Follow)​

r r s e / o o s e / r o s e / r o s e

The pattern will be follow: r o s e

Thus, correct option is (b).s