Find the correct combination of the words that should replace each other to make both sentences contextually meaningful.

(I) The concert (A) was sold out, so we had to obtain (B) tickets from a scalper (C),

(II) the tickets turned (D) out to be spurious (E), so we had to find a way (F) to get our money back.

The correct option is No replacement required.

To determine if any words need to be replaced, let us analyze the context and grammatical correctness of each sentence step-by-step:

Step 1: Analyze Sentence (I)
Sentence (I) reads: "The concert (A) was sold out, so we had to obtain (B) tickets from a scalper (C),"
- (A) "was": Grammatically correct as it serves as the auxiliary verb for the passive construction "was sold out".
- (B) "obtain": Contextually appropriate because if a concert is sold out, one must "obtain" (get/acquire) tickets through alternative means.
- (C) "scalper": A scalper is a person who buys tickets for an event and resells them at a much higher, often unauthorized price. This fits the scenario of a sold-out concert perfectly.
Since all three highlighted words in Sentence (I) are contextually and grammatically accurate, no changes are needed here.

Step 2: Analyze Sentence (II)
Sentence (II) reads: "the tickets turned (D) out to be spurious (E), so we had to find a way (F) to get our money back."
- (D) "turned": Forms the phrasal verb "turned out", which means to prove to be the case.
- (E) "spurious": Means fake, counterfeit, or invalid. Counterfeit tickets bought from a scalper fit this description perfectly.
- (F) "way": Fits the idiomatic phrase "find a way", meaning to discover a method or plan to resolve a problem (in this case, getting their money back after realizing the tickets were fake).
All highlighted words in Sentence (II) are contextually and grammatically correct in their current positions.

Conclusion:
Both sentences make complete logical and grammatical sense without swapping any words. Therefore, no replacement is required.