Select the option that represents the letters that, when sequentially placed from left to right in the blanks, will complete the letter series. s _ _ u _ a r _ s t _ a a _ s _ _ u a _ r

s t a u s r s t a s t a s u r s t a s t a r u s s t a s t a s u s r t a

s t a s u r s t a

s s t u a a r / s s t u a a r / s s t u a a r s t a s u r s t a