(A) The guard pleaded ______ the Principal for mercy.
- "Pleaded with" - correct usage when addressing a plea to someone in authority
(B) You must not quarrel ______ the issue of parental property.
- "Quarrel over" - correct usage when arguing about something
(C) He lives entirely ______ carbohydrates.
- "Lives on" - correct usage meaning to survive on or depend on for sustenance
(D) She was indebted ______ her friends for their timely help.
- "Indebted to" - correct usage meaning owing gratitude to someone
Hence, Option 4: (A) - (III), (B) - (I), (C) - (IV), (D) - (II) → provides the grammatically correct prepositions for all four sentences → correct