Option B uses the required Constraint Modeling Language structure for establishing arequire relationshipbetween two product relations. The model first declares the Desktop and Monitor relations with cardinalities [0..99], allowing zero or multiple instances in the quote context. The require() rule then establishes the dependency that whenever the relevant Desktop relation is present, Monitor must also be present.

The rule also includes the meaningful message " Desktop requires Monitor " , which communicates the configuration dependency to users or supports constraint evaluation feedback. The result is configuration-time enforcement rather than downstream detection of an invalid quote.

Option A is incorrect because constraint(desktop, monitor...) does not express the required product dependency using the appropriate require() construct. Option C omits the cardinality declarations and inconsistently references the type names rather than correctly applying the declared relations in the required-rule expression.

Constraint rules are valuable because they prevent incomplete or incompatible configurations while the transaction is being configured. In this scenario, the desired relationship is not merely validation; Monitor is mandatory whenever Desktop is selected.

Study Guide Reference:Configure, Price, Quote — Product Configuration; Constraint Modeling Language; require rules; relation cardinality.

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