Choose or find odd letter group - PENAL , IDHNI , RUUD , KRTSINSA

A. PENAL

Choose or find odd number - 751, 734, 981, 853, 532

A. 751

Choose analogous pair - Badminton : Court

C. SKATING : RINK

Number of letters skipped in between adjacent letters in the series are multiples of 3.
Which of the following series observes this rule ?

A. AELPZ

Choose analogous pair - Incandescent : Glowing

D. INDEFATIGABLE : UNTIRING