Many early attempts were made to reach the top of Mount Everest; George Mallory and Guy Bullock tried in 1921.
The official meaning of partner in the English language is ''a person who takes part in an undertaking with another or others, especially in a business or firm with shared risks and profits.''
But there are other ways to use partner, a partner can be a companion such as a friend. Another meaning of partner can be a love interest such as a spouse.
Raucos rock, slow swig and beautiful big band songs
The correct option is B.
You can test if there are two independent clauses by separating the clauses and seeing if they can stand alone.
They hadn't planned the trip. They returned to the store the next day and bought more peanut brittle.
Since the the two clauses can stand alone, there are two independent clauses.
Two independent clauses constitute a compound sentence.