Answer:
did you read the book or article
Explanation:
The sentence in which the adverb clause modifies an adjective is the second one - The veteran appeared proud as he saluted the flag.
The adjective here is <em>proud</em>, and the adverbial clause is <em>as he saluted the flag. </em>As you can see here, that clause is describing the adjective in more detail.
When did the veteran appear proud? - As he saluted the flag (it obviously modifies the word <em>proud</em>)
A cause-and-effect relationship is signaled by the words "But since."
The fourth excerpt should be right
