Final answer:
The selected run-on sentence is: Putting cocoa and baking powder on the list he wanted to make chocolate brownies and spend the rest of the night reading it was relaxing to him.
Step-by-step explanation:
The run-on sentence is: Putting cocoa and baking powder on the list he wanted to make chocolate brownies and spend the rest of the night reading it was relaxing to him.
A run-on sentence is a sentence in which two or more complete sentences are not separated by any punctuation. In this case, the sentence contains multiple independent clauses without proper punctuation or coordination.
To fix the run-on sentence, you can separate the independent clauses with a coordinating conjunction, add a period to create two sentences, or use a semicolon to separate them. For example, you could rewrite the sentence as: He wanted to make chocolate brownies and spend the rest of the night reading. Putting cocoa and baking powder on the list was relaxing to him.