Find the missing term in the following series: C, I, O, U, ?

Which of the following letter-number clusters will replace the question mark (?) in the given series to make it logically complete? CAR78, GEV86, KIZ94, OMD102, ?

Refer to the following letter series and answer the question: (Left) A B E R F S Q B S Z S S A E H L V X Y (Right) How many vowels are there, each of which is immediately preceded by a vowel and also immediately followed by a consonant?