Which letter-cluster will replace the question mark (?) to complete the given series?

PQST, TOVS, ?, BKBQ, FIEP

Select the option that represents the letters that, when placed from left to right in the following blanks, will complete the letter-series.

S _ U C T S R _ _ T _ R U E _ S R _ _ T

In a certain code language, ‘FARM’ is coded as HDTP and ‘EGGS’ is coded as GJIV. How will ‘FOOD’ be coded in the same language?

Select the option that is related to the fifth letter-cluster in the same way as the second letter-cluster is related to the first letter-cluster and the fourth letter-cluster is related to the third letter cluster.

COMFORT : FMOCTRO :: DIGNITY : NGIDYTI :: FOREIGN : ?