Consider the following generalization/specialization.

1. The relational model does not allow one to enforce the completeness constraint; the disjointness constraint can be enforced.

2. The relational model does not allow one to enforce both the completeness constraint and the disjointness constraint.

3. By dropping the relation “Discipline” in the relational model, the completeness constraint can be enforced.

4. The relational model allows the specialization to be partial.

Which of the following options is correct?

a. Statements 1 and 2 are both correct.

b. Statements 1 and 4 are both incorrect.

c. Only statement 1 is incorrect, the other statements are correct.

d. Only statement 4 is incorrect, the other statements are correct.

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INDIVIDUAL DISCIPLINE t d Discipline nr Name TEAM SPORT Number players Suppose we represent this generalization/specialization by the following relational model: Discipline (Disciplinenr, Name) Individual sport (Disciplinenr) Disciplinenr refers to Disciplinenr in Discipline Teamsport (Disciplinenr, Number players) Disciplinenr refers to Disciplinenr in Discipline Consider the following four statements: