Three of the following letter-number groups are alike in a certain way and form a group. Select the one that is incompatible with the rest.

Select the option that sequentially completes the letter series when placed from left to right in the blanks: _ tu _ rt _ s _ _ usrtu

Select the alphanumeric group that will come in place of the question mark (?) in the given series to complete it logically. Series: D5A, F9C, H13E, J17G, ?