That would be a practical exercise. Practical means the actual doing or use of something rather than with theory and ideas. So it would apply to real life situations.
Hope this helps!
I think the answer is c. Sentence 3
Sorry if wrong
It is a A. simple sentence, because there is only one main verb - opened.
A compound sentence has at least two independent clauses, a complex sentence has an independent clause and at least one dependent, a compound-complex clause sentence has two independent clauses and at least one dependent.
