Answer:
I believe the best classification for the sentence is compound-complex.
Explanation:
A compound-complex sentence is comprised of two independent clauses and one dependent one. Let's remember that an independent clause is one capable of expressing a complete thought on its own. A dependent clause, on the other hand, does not express a complete thought. Instead, it depends on the main clause to make sense. When we join independent clauses, we use coordinating conjunctions. When we introduce a dependent clause, we use a subordinating conjunction. Let's take a look at our sentence:
Because they provide toys for children, fast food restaurants like McDonald's have become immensely popular among families, and the price of a Happy Meal makes them a great choice for parents as well as kids.
Notice that we have two independent clauses that can express a complete thought on their own:
1. fast food restaurants like McDonald's have become immensely popular among families
2. the price of a Happy Meal makes them a great choice for parents as well as kids
Those two clauses are joined by a comma and the coordinating conjunction "and":
-- fast food restaurants like McDonald's have become immensely popular among families, and the price of a Happy Meal makes them a great choice for parents as well as kids.
Prior to the first independent clause, we have a dependent one, introduced by the subordinating conjunction "because". Notice how it does not make complete sense on its own:
3. Because they provide toys for children
There is information missing. But, when we place together it with the main clauses, it makes sense:
Because they provide toys for children, fast food restaurants like McDonald's have become immensely popular among families, and the price of a Happy Meal makes them a great choice for parents as well as kids.
