which is a correctly formed compound sentence?\ndaniel was very excited to watch his favorite team play. but…

Brief Explanations:

A compound - sentence combines two independent clauses. In English, when using a coordinating conjunction like "but" to join two independent clauses, a comma is placed before the conjunction. The first option has "But" capitalized as a new sentence which is incorrect for a compound - sentence structure. The second option lacks the necessary comma. The fourth option incorrectly uses a semicolon along with "but"; a semicolon is used to join independent clauses without a coordinating conjunction or with a conjunctive adverb.

Answer:

Daniel was very excited to watch his favorite team play, but they lost.