An adjective clause modifies a noun and usually begins with a relative pronoun like who, which, that, where, or when. In A, the whose clause acts as the object of know, so it is a noun clause. In B, the that clause is a noun clause complementing glad. In C, as I was late is an adverb clause of reason. In D, where they will come modifies place, and in E, when we met modifies day, so both D and E are adjective clauses.